A class to determine the decomposition of a unitary into a sequence of CNOT and U3 operations. More...

#include <N_Qubit_Decomposition.h>

Inheritance diagram for N_Qubit_Decomposition:

[legend]

Public Member Functions
void	add_cnot_to_end (int control_qbit, int target_qbit)
	Append a C_NOT gate operation to the list of operations. More...

void	add_cnot_to_front (int control_qbit, int target_qbit)
	Add a C_NOT gate operation to the front of the list of operations. More...

void	add_operation_to_end (Operation *operation)
	Append a general operation to the list of operations. More...

void	add_operation_to_front (Operation *operation)
	Add an operation to the front of the list of operations. More...

void	add_operations_to_end (std::vector< Operation * > operations_in)
	Append a list of operations to the list of operations. More...

void	add_operations_to_front (std::vector< Operation * > operations_in)
	Add an array of operations to the front of the list of operations. More...

void	add_u3_to_end (int target_qbit, bool Theta, bool Phi, bool Lambda)
	Append a U3 gate to the list of operations. More...

void	add_u3_to_front (int target_qbit, bool Theta, bool Phi, bool Lambda)
	Add a U3 gate to the front of the list of operations. More...

Matrix	apply_operation (Matrix &operation_mtx, Matrix &input_matrix)
	Apply an operations on the input matrix. More...

bool	check_optimization_solution ()
	check_optimization_solution More...

N_Qubit_Decomposition *	clone ()
	Create a clone of the present class. More...

void	combine (Operation_block *op_block)
	Call to append the operations of an operation block to the current block. More...

void	decompose_submatrix ()
	Start the decompostion process to recursively decompose the submatrices. More...

int	extract_operations (Operation_block *op_block)
	Call to extract the operations stored in the class. More...

void	extract_subdecomposition_results (Sub_Matrix_Decomposition *cSub_decomposition)
	Call to extract and store the calculated parameters and operations of the sub-decomposition processes. More...

void	final_optimization ()
	final optimization procedure improving the accuracy of the decompositin when all the qubits were already disentangled. More...

void	finalize_decomposition ()
	After the main optimization problem is solved, the indepent qubits can be rotated into state \|0> by this def. More...

int	get_control_qbit ()
	Call to get the index of the control qubit. More...

Matrix	get_decomposed_matrix ()
	Calculate the decomposed matrix resulted by the effect of the optimized operations on the unitary Umtx. More...

double	get_decomposition_error ()
	Call to get the error of the decomposition. More...

Matrix	get_finalizing_operations (Matrix &mtx, Operation_block finalizing_operations, double finalizing_parameters)
	This method determine the operations needed to rotate the indepent qubits into the state \|0> More...

gates_num	get_gate_nums ()
	Call to get the number of the individual gate types in the list of operations. More...

std::vector< int >	get_involved_qubits ()
	Call to get the qubits involved in the operations stored in the block of operations. More...

std::vector< Matrix >	get_matrices (const double *parameters)
	Call to get the list of matrix representation of the operations grouped in the block. More...

Matrix	get_matrix (const double *parameters)
	Call to retrieve the operation matrix (Which is the product of all the operation matrices stored in the operation block) More...

Matrix	get_matrix ()
	Call to retrieve the operation matrix. More...

int	get_operation (unsigned int n, operation_type &type, int &target_qbit, int &control_qbit, double *parameters)
	Call to prepare the optimized operations to export. More...

int	get_operation_num ()
	Call to get the number of operations grouped in the class. More...

std::vector< Matrix, tbb::cache_aligned_allocator< Matrix > >	get_operation_products (double parameters, std::vector< Operation >::iterator operations_it, int num_of_operations)
	Calculate the list of gate operation matrices such that the i>0-th element in the result list is the product of the operations of all 0<=n<i operations from the input list and the 0th element in the result list is the identity. More...

std::vector< Operation * >	get_operations ()
	Call to get the operations stored in the class. More...

double *	get_optimized_parameters ()
	Call to get the optimized parameters. More...

void	get_optimized_parameters (double *ret)
	Call to get the optimized parameters. More...

int	get_parameter_num ()
	Call to get the number of free parameters. More...

int	get_qbit_num ()
	Call to get the number of qubits composing the unitary. More...

int	get_target_qbit ()
	Call to get the index of the target qubit. More...

Matrix	get_transformed_matrix (const double parameters, std::vector< Operation >::iterator operations_it, int num_of_operations)
	Calculate the transformed matrix resulting by an array of operations on the matrix Umtx. More...

Matrix	get_transformed_matrix (const double parameters, std::vector< Operation >::iterator operations_it, int num_of_operations, Matrix &initial_matrix)
	Calculate the transformed matrix resulting by an array of operations on a given initial matrix. More...

operation_type	get_type ()
	Call to get the type of the operation. More...

Matrix	get_Umtx ()
	Call to retrive a pointer to the unitary to be transformed. More...

int	get_Umtx_size ()
	Call to get the size of the unitary to be transformed. More...

void	list_operations (int start_index)
	Call to print the operations decomposing the initial unitary. More...

void	list_operations (const double *parameters, int start_index)
	Call to print the list of operations stored in the block of operations for a specific set of parameters. More...

	N_Qubit_Decomposition (Matrix Umtx_in, int qbit_num_in, bool optimize_layer_num_in, guess_type initial_guess_in)
	Constructor of the class. More...

double	optimization_problem (const double *parameters)
	The optimization problem of the final optimization. More...

void	prepare_operations_to_export ()
	Call to prepare the optimized operations to export. More...

std::vector< Operation * >	prepare_operations_to_export (std::vector< Operation * > ops, const double *parameters)
	Call to prepare the optimized operations to export. More...

std::vector< Operation * >	prepare_operations_to_export (Operation_block block_op, const double parameters)
	Call to prepare the operations of an operation block to export. More...

void	release_operations ()
	Call to release the stored operations. More...

void	reorder_qubits (std::vector< int > qbit_list)
	Call to reorder the qubits in the matrix of the operation. More...

int	set_identical_blocks (int n, int identical_blocks_in)
	Set the number of identical successive blocks during the subdecomposition of the n-th qubit. More...

int	set_identical_blocks (std::map< int, int > identical_blocks_in)
	Set the number of identical successive blocks during the subdecomposition of the n-th qubit. More...

int	set_iteration_loops (int n, int iteration_loops_in)
	Set the number of iteration loops during the subdecomposition of the n-th qubit. More...

int	set_iteration_loops (std::map< int, int > iteration_loops_in)
	Set the number of iteration loops during the subdecomposition of the qbit-th qubit. More...

void	set_matrix (Matrix input)
	Call to set the stored matrix in the operation. More...

void	set_max_iteration (int max_iterations_in)
	Call to set the maximal number of the iterations in the optimization process. More...

int	set_max_layer_num (int n, int max_layer_num_in)
	Set the maximal number of layers used in the subdecomposition of the n-th qubit. More...

int	set_max_layer_num (std::map< int, int > max_layer_num_in)
	Set the maximal number of layers used in the subdecomposition of the n-th qubit. More...

void	set_optimization_blocks (int optimization_block_in)
	Call to set the number of operation blocks to be optimized in one shot. More...

void	set_qbit_num (int qbit_num_in)
	Set the number of qubits spanning the matrix of the operations stored in the block of operations. More...

void	set_verbose (bool verbose_in)
	Call to set the verbose attribute to true or false. More...

int	simplify_layer (Operation_block layer, double parameters, unsigned int parameter_num_block, std::map< int, int > max_layer_num_loc, Operation_block &simplified_layer, double &simplified_parameters, unsigned int &simplified_parameter_num)
	Call to simplify the gate structure in a block of operations (i.e. More...

void	simplify_layers ()
	Call to simplify the gate structure in the layers if possible (i.e. More...

void	solve_layer_optimization_problem (int num_of_parameters, gsl_vector *solution_guess_gsl)
	Call to solve layer by layer the optimization problem. More...

void	solve_optimization_problem (double *solution_guess, int solution_guess_num)
	This method can be used to solve the main optimization problem which is devidid into sub-layer optimization processes. More...

void	start_decomposition (bool finalize_decomp, bool prepare_export)
	Start the disentanglig process of the unitary. More...

	~N_Qubit_Decomposition ()
	Destructor of the class. More...

Static Public Member Functions
static void	Init_max_layer_num ()
	Initializes default layer numbers. More...

static double	optimization_problem (const gsl_vector parameters, void void_instance)
	The optimization problem of the final optimization. More...

static void	optimization_problem_combined (const gsl_vector parameters, void void_instance, double f0, gsl_vector grad)
	Call to calculate both the cost function and the its gradient components. More...

static void	optimization_problem_grad (const gsl_vector parameters, void void_instance, gsl_vector *grad)
	Calculate the approximate derivative (f-f0)/(x-x0) of the cost function with respect to the free parameters. More...

Public Attributes
int	optimization_block
	number of operation blocks used in one shot of the optimization process More...

double	optimization_tolerance
	The maximal allowed error of the optimization problem. More...

bool	verbose
	Logical variable. Set true for verbose mode, or to false to suppress output messages. More...

Static Public Attributes
static std::map< int, int >	max_layer_num_def
	A map of <int n: int num> indicating that how many layers should be used in the subdecomposition process by default for the subdecomposing of the nth qubits. More...

Protected Attributes
int	control_qbit
	The index of the qubit which acts as a control qubit (control_qbit >= 0) in controlled operations. More...

double	current_minimum
	The current minimum of the optimization problem. More...

double	decomposition_error
	error of the unitarity of the final decomposition More...

bool	decomposition_finalized
	logical value describing whether the decomposition was finalized or not (i.e. whether the decomposed qubits were rotated into the state \|0> or not) More...

int	finalizing_operations_num
	number of finalizing (deterministic) opertaions rotating the disentangled qubits into state \|0>. More...

int	finalizing_parameter_num
	the number of the finalizing (deterministic) parameters of operations rotating the disentangled qubits into state \|0>. More...

double	global_target_minimum
	The global target minimum of the optimization problem. More...

std::map< int, int >	identical_blocks
	A map of <int n: int num> indicating that how many identical succesive blocks should be used in the disentanglement of the nth qubit from the others. More...

guess_type	initial_guess
	type to guess the initial values for the optimization. Possible values: ZEROS=0, RANDOM=1, CLOSE_TO_ZERO=2 More...

std::map< int, int >	iteration_loops
	A map of <int n: int num> indicating the number of iteration in each step of the decomposition. More...

int	layer_num
	number of operation layers More...

int	matrix_size
	The size N of the NxN matrix associated with the operations. More...

int	max_iterations
	Maximal number of iterations allowed in the optimization process. More...

std::map< int, int >	max_layer_num
	A map of <int n: int num> indicating that how many layers should be used in the subdecomposition process for the subdecomposing of the nth qubits. More...

int	num_threads
	Number of outer OpenMP threads. (During the calculations OpenMP multithreading is turned off.) More...

std::vector< Operation * >	operations
	The list of stored operations. More...

bool	optimization_problem_solved
	logical value describing whether the optimization problem was solved or not More...

bool	optimize_layer_num
	logical value. Set true to optimize the minimum number of operation layers required in the decomposition, or false when the predefined maximal number of layer gates is used (ideal for general unitaries). More...

double *	optimized_parameters
	The optimized parameters for the operations. More...

unsigned int	parameter_num
	the number of free parameters of the operation More...

int	qbit_num
	number of qubits spanning the matrix of the operation More...

int	target_qbit
	The index of the qubit on which the operation acts (target_qbit >= 0) More...

operation_type	type
	The type of the operation (see enumeration operation_type) More...

Matrix	Umtx
	The unitary to be decomposed. More...

Detailed Description

A class to determine the decomposition of a unitary into a sequence of CNOT and U3 operations.

Definition at line 36 of file N_Qubit_Decomposition.h.

Constructor & Destructor Documentation

◆ N_Qubit_Decomposition()

N_Qubit_Decomposition::N_Qubit_Decomposition	(	Matrix	Umtx_in,
		int	qbit_num_in,
		bool	optimize_layer_num_in,
		guess_type	initial_guess_in = `CLOSE_TO_ZERO`
	)

Constructor of the class.

Parameters

Umtx_in	The unitary matrix to be decomposed
qbit_num_in	The number of qubits spanning the unitary Umtx
optimize_layer_num_in	Optional logical value. If true, then the optimization tries to determine the lowest number of the layers needed for the decomposition. If False (default), the optimization is performed for the maximal number of layers.
initial_guess_in	Enumeration element indicating the method to guess initial values for the optimization. Possible values: 'zeros=0' ,'random=1', 'close_to_zero=2'

Returns: An instance of the class

Definition at line 35 of file N_Qubit_Decomposition.cpp.

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◆ ~N_Qubit_Decomposition()

N_Qubit_Decomposition::~N_Qubit_Decomposition ( )

Destructor of the class.

Definition at line 64 of file N_Qubit_Decomposition.cpp.

Member Function Documentation

◆ add_cnot_to_end()

void Operation_block::add_cnot_to_end	(	int	control_qbit,
		int	target_qbit
	)

inherited

Append a C_NOT gate operation to the list of operations.

Parameters

control_qbit	The identification number of the control qubit. (0 <= target_qbit <= qbit_num-1)
target_qbit	The identification number of the target qubit. (0 <= target_qbit <= qbit_num-1)

Definition at line 264 of file Operation_block (copy).cpp.

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◆ add_cnot_to_front()

void Operation_block::add_cnot_to_front	(	int	control_qbit,
		int	target_qbit
	)

inherited

Add a C_NOT gate operation to the front of the list of operations.

Parameters

control_qbit	The identification number of the control qubit. (0 <= target_qbit <= qbit_num-1)
target_qbit	The identification number of the target qubit. (0 <= target_qbit <= qbit_num-1)

Definition at line 281 of file Operation_block (copy).cpp.

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◆ add_operation_to_end()

void Operation_block::add_operation_to_end ( Operation * operation )

inherited

Append a general operation to the list of operations.

Parameters

operation A pointer to a class Operation describing an operation.

Definition at line 322 of file Operation_block (copy).cpp.

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◆ add_operation_to_front()

void Operation_block::add_operation_to_front ( Operation * operation )

inherited

Add an operation to the front of the list of operations.

Parameters

operation A pointer to a class Operation describing an operation.

Definition at line 345 of file Operation_block (copy).cpp.

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◆ add_operations_to_end()

void Operation_block::add_operations_to_end ( std::vector< Operation * > operations_in )

inherited

Append a list of operations to the list of operations.

Parameters

operations_in A list of operation class instances.

Definition at line 295 of file Operation_block (copy).cpp.

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◆ add_operations_to_front()

void Operation_block::add_operations_to_front ( std::vector< Operation * > operations_in )

inherited

Add an array of operations to the front of the list of operations.

Parameters

operations_in A list of operation class instances.

Definition at line 308 of file Operation_block (copy).cpp.

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◆ add_u3_to_end()

void Operation_block::add_u3_to_end	(	int	target_qbit,
		bool	Theta,
		bool	Phi,
		bool	Lambda
	)

inherited

Append a U3 gate to the list of operations.

Parameters

target_qbit	The identification number of the targt qubit. (0 <= target_qbit <= qbit_num-1)
Theta	The Theta parameter of the U3 operation
Phi	The Phi parameter of the U3 operation
Lambda	The Lambda parameter of the U3 operation

Definition at line 233 of file Operation_block (copy).cpp.

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◆ add_u3_to_front()

void Operation_block::add_u3_to_front	(	int	target_qbit,
		bool	Theta,
		bool	Phi,
		bool	Lambda
	)

inherited

Add a U3 gate to the front of the list of operations.

Parameters

target_qbit	The identification number of the targt qubit. (0 <= target_qbit <= qbit_num-1)
Theta	The Theta parameter of the U3 operation
Phi	The Phi parameter of the U3 operation
Lambda	The Lambda parameter of the U3 operation

Definition at line 249 of file Operation_block (copy).cpp.

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◆ apply_operation()

Matrix Decomposition_Base::apply_operation	(	Matrix &	operation_mtx,
		Matrix &	input_matrix
	)

inherited

Apply an operations on the input matrix.

Parameters

operation_mtx	The matrix of the operation.
input_matrix	The input matrix to be transformed.

Returns: Returns with the transformed matrix

Definition at line 711 of file Decomposition_Base.cpp.

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◆ check_optimization_solution()

bool Decomposition_Base::check_optimization_solution ( )

inherited

check_optimization_solution

Checks the convergence of the optimization problem.

Returns: Returns with true if the target global minimum was reached during the optimization process, or false otherwise.

Definition at line 568 of file Decomposition_Base.cpp.

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◆ clone()

N_Qubit_Decomposition * N_Qubit_Decomposition::clone ( )

Create a clone of the present class.

Returns: Return with a pointer pointing to the cloned object.

Definition at line 885 of file N_Qubit_Decomposition.cpp.

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◆ combine()

void Operation_block::combine ( Operation_block * op_block )

inherited

Call to append the operations of an operation block to the current block.

Parameters

op_block A pointer to an instance of class Operation_block

Definition at line 593 of file Operation_block (copy).cpp.

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◆ decompose_submatrix()

void N_Qubit_Decomposition::decompose_submatrix ( )

Start the decompostion process to recursively decompose the submatrices.

Definition at line 248 of file N_Qubit_Decomposition.cpp.

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◆ extract_operations()

int Operation_block::extract_operations ( Operation_block * op_block )

inherited

Call to extract the operations stored in the class.

Parameters

op_block An instance of Operation_block class in which the operations will be stored. (The current operations will be erased)

Returns: Return with 0 on success.

Definition at line 686 of file Operation_block (copy).cpp.

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◆ extract_subdecomposition_results()

void N_Qubit_Decomposition::extract_subdecomposition_results ( Sub_Matrix_Decomposition * cSub_decomposition )

Call to extract and store the calculated parameters and operations of the sub-decomposition processes.

Parameters

cSub_decomposition An instance of class Sub_Matrix_Decomposition used to disentangle the n-th qubit from the others.

Definition at line 187 of file N_Qubit_Decomposition.cpp.

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◆ final_optimization()

void N_Qubit_Decomposition::final_optimization ( )

final optimization procedure improving the accuracy of the decompositin when all the qubits were already disentangled.

Definition at line 352 of file N_Qubit_Decomposition.cpp.

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◆ finalize_decomposition()

void Decomposition_Base::finalize_decomposition ( )

inherited

After the main optimization problem is solved, the indepent qubits can be rotated into state |0> by this def.

The constructed operations are added to the array of operations needed to the decomposition of the input unitary.

Definition at line 132 of file Decomposition_Base.cpp.

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◆ get_control_qbit()

int Operation::get_control_qbit ( )

inherited

Call to get the index of the control qubit.

Returns: Return with the index of the control qubit (return with -1 if control qubit was not set)

Definition at line 157 of file Operation.cpp.

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◆ get_decomposed_matrix()

Matrix Decomposition_Base::get_decomposed_matrix ( )

inherited

Calculate the decomposed matrix resulted by the effect of the optimized operations on the unitary Umtx.

Returns: Returns with the decomposed matrix.

Definition at line 699 of file Decomposition_Base.cpp.

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◆ get_decomposition_error()

double Decomposition_Base::get_decomposition_error ( )

inherited

Call to get the error of the decomposition.

Returns: Returns with the error of the decomposition

Definition at line 1059 of file Decomposition_Base.cpp.

◆ get_finalizing_operations()

Matrix Decomposition_Base::get_finalizing_operations	(	Matrix &	mtx,
		Operation_block *	finalizing_operations,
		double *	finalizing_parameters
	)

inherited

This method determine the operations needed to rotate the indepent qubits into the state |0>

Parameters

mtx	The unitary describing indepent qubits. The resulting matrix is returned by this pointer
finalizing_operations	Pointer pointig to a block of operations containing the final operations.
finalizing_parameters	Parameters corresponding to the finalizing operations.

Returns: Returns with the finalized matrix

Definition at line 203 of file Decomposition_Base.cpp.

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◆ get_gate_nums()

gates_num Operation_block::get_gate_nums ( )

inherited

Call to get the number of the individual gate types in the list of operations.

Returns: Returns with an instance gates_num describing the number of the individual gate types

Definition at line 369 of file Operation_block (copy).cpp.

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◆ get_involved_qubits()

std::vector< int > Operation_block::get_involved_qubits ( )

inherited

Call to get the qubits involved in the operations stored in the block of operations.

Returns: Return with a list of the invovled qubits

Definition at line 552 of file Operation_block (copy).cpp.

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◆ get_matrices()

std::vector< Matrix > Operation_block::get_matrices ( const double * parameters )

inherited

Call to get the list of matrix representation of the operations grouped in the block.

Parameters

parameters Array of parameters to calculate the matrix of the operation block

Returns: Returns with the list of the operations

Definition at line 174 of file Operation_block (copy).cpp.

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◆ get_matrix() [1/2]

Matrix Operation_block::get_matrix ( const double * parameters )

inherited

Call to retrieve the operation matrix (Which is the product of all the operation matrices stored in the operation block)

Parameters

parameters An array pointing to the parameters of the operations

Returns: Returns with the operation matrix

Definition at line 106 of file Operation_block (copy).cpp.

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◆ get_matrix() [2/2]

Matrix Operation::get_matrix ( )

inherited

Call to retrieve the operation matrix.

Returns: Returns with a matrix of the operation

Definition at line 97 of file Operation.cpp.

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◆ get_operation()

int Decomposition_Base::get_operation	(	unsigned int	n,
		operation_type &	type,
		int &	target_qbit,
		int &	control_qbit,
		double *	parameters
	)

inherited

Call to prepare the optimized operations to export.

Parameters

n	Integer labeling the n-th oepration (n>=0).
type	The type of the operation from enumeration operation_type is returned via this parameter.
target_qbit	The ID of the target qubit is returned via this input parameter.
control_qbit	The ID of the control qubit is returned via this input parameter.
parameters	The parameters of the operations

Returns: Returns with 0 if the export of the n-th operation was successful. If the n-th operation does not exists, -1 is returned. If the operation is not allowed to be exported, i.e. it is not a CNOT or U3 operation, then -2 is returned.

Definition at line 1009 of file Decomposition_Base.cpp.

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◆ get_operation_num()

int Operation_block::get_operation_num ( )

inherited

Call to get the number of operations grouped in the class.

Returns: Return with the number of the operations grouped in the operation block.

Definition at line 418 of file Operation_block (copy).cpp.

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◆ get_operation_products()

std::vector< Matrix, tbb::cache_aligned_allocator< Matrix > > Decomposition_Base::get_operation_products	(	double *	parameters,
		std::vector< Operation * >::iterator	operations_it,
		int	num_of_operations
	)

inherited

Calculate the list of gate operation matrices such that the i>0-th element in the result list is the product of the operations of all 0<=n<i operations from the input list and the 0th element in the result list is the identity.

Parameters

parameters	An array containing the parameters of the U3 operations.
operations_it	An iterator pointing to the forst operation.
num_of_operations	The number of operations involved in the calculations

Returns: Returns with a vector of the product matrices.

Parameters

parameters	An array containing the parameters of the operations.
operations_it	An iterator pointing to the first operation.
num_of_operations	The number of operations involved in the calculations

Returns: Returns with a vector of the product matrices.

Definition at line 35 of file Functor_Get_Operation_Products.cpp.

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◆ get_operations()

std::vector< Operation * > Operation_block::get_operations ( )

inherited

Call to get the operations stored in the class.

Returns: Return with a list of the operations.

Definition at line 584 of file Operation_block (copy).cpp.

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◆ get_optimized_parameters() [1/2]

double * Decomposition_Base::get_optimized_parameters ( )

inherited

Call to get the optimized parameters.

Returns: Return with the pointer pointing to the array storing the optimized parameters

Definition at line 596 of file Decomposition_Base.cpp.

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◆ get_optimized_parameters() [2/2]

void Decomposition_Base::get_optimized_parameters ( double * ret )

inherited

Call to get the optimized parameters.

Parameters

ret	Preallocated array to store the optimized parameters.

Definition at line 606 of file Decomposition_Base.cpp.

◆ get_parameter_num()

int Operation_block::get_parameter_num ( )

inherited

Call to get the number of free parameters.

Returns: Return with the number of parameters of the operations grouped in the operation block.

Definition at line 409 of file Operation_block (copy).cpp.

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◆ get_qbit_num()

int Operation::get_qbit_num ( )

inherited

Call to get the number of qubits composing the unitary.

Returns: Return with the number of qubits composing the unitary

Definition at line 183 of file Operation.cpp.

◆ get_target_qbit()

int Operation::get_target_qbit ( )

inherited

Call to get the index of the target qubit.

Returns: Return with the index of the target qubit (return with -1 if target qubit was not set)

Definition at line 149 of file Operation.cpp.

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◆ get_transformed_matrix() [1/2]

Matrix Decomposition_Base::get_transformed_matrix	(	const double *	parameters,
		std::vector< Operation * >::iterator	operations_it,
		int	num_of_operations
	)

inherited

Calculate the transformed matrix resulting by an array of operations on the matrix Umtx.

Parameters

parameters	An array containing the parameters of the U3 operations.
operations_it	An iterator pointing to the first operation to be applied on the initial matrix.
num_of_operations	The number of operations to be applied on the initial matrix

Returns: Returns with the transformed matrix.

Definition at line 619 of file Decomposition_Base.cpp.

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◆ get_transformed_matrix() [2/2]

Matrix Decomposition_Base::get_transformed_matrix	(	const double *	parameters,
		std::vector< Operation * >::iterator	operations_it,
		int	num_of_operations,
		Matrix &	initial_matrix
	)

inherited

Calculate the transformed matrix resulting by an array of operations on a given initial matrix.

Parameters

parameters	An array containing the parameters of the U3 operations.
operations_it	An iterator pointing to the first operation to be applied on the initial matrix.
num_of_operations	The number of operations to be applied on the initial matrix
initial_matrix	The initial matrix wich is transformed by the given operations.

Returns: Returns with the transformed matrix.

Parameters

parameters	An array containing the parameters of the U3 operations.
operations_it	An iterator pointing to the first operation to be applied on the initial matrix.
num_of_operations	The number of operations to be applied on the initial matrix
initial_matrix	The initial matrix wich is transformed by the given operations. (by deafult it is set to the attribute Umtx)

Returns: Returns with the transformed matrix.

Definition at line 634 of file Decomposition_Base.cpp.

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◆ get_type()

operation_type Operation::get_type ( )

inherited

Call to get the type of the operation.

Returns: Return with the type of the operation (see operation_type for details)

Definition at line 174 of file Operation.cpp.

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◆ get_Umtx()

Matrix Decomposition_Base::get_Umtx ( )

inherited

Call to retrive a pointer to the unitary to be transformed.

Returns: Return with the unitary Umtx

Definition at line 579 of file Decomposition_Base.cpp.

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◆ get_Umtx_size()

int Decomposition_Base::get_Umtx_size ( )

inherited

Call to get the size of the unitary to be transformed.

Returns: Return with the size N of the unitary NxN

Definition at line 588 of file Decomposition_Base.cpp.

◆ Init_max_layer_num()

void Decomposition_Base::Init_max_layer_num ( )

staticinherited

Initializes default layer numbers.

Definition at line 853 of file Decomposition_Base.cpp.

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◆ list_operations() [1/2]

void Decomposition_Base::list_operations ( int start_index )

inherited

Call to print the operations decomposing the initial unitary.

These operations brings the intial matrix into unity.

Parameters

start_index The index of the first operation

Definition at line 188 of file Decomposition_Base.cpp.

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◆ list_operations() [2/2]

void Operation_block::list_operations	(	const double *	parameters,
		int	start_index
	)

inherited

Call to print the list of operations stored in the block of operations for a specific set of parameters.

Parameters

parameters	The parameters of the operations that should be printed.
start_index	The ordinal number of the first operation.

Definition at line 428 of file Operation_block (copy).cpp.

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◆ optimization_problem() [1/2]

double N_Qubit_Decomposition::optimization_problem ( const double * parameters )

virtual

The optimization problem of the final optimization.

Parameters

parameters An array of the free parameters to be optimized. (The number of teh free paramaters should be equal to the number of parameters in one sub-layer)

Returns: Returns with the cost function. (zero if the qubits are desintangled.)

Reimplemented from Decomposition_Base.

Definition at line 472 of file N_Qubit_Decomposition.cpp.

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◆ optimization_problem() [2/2]

double N_Qubit_Decomposition::optimization_problem	(	const gsl_vector *	parameters,
		void *	void_instance
	)

static

The optimization problem of the final optimization.

Parameters

parameters	A GNU Scientific Library containing the parameters to be optimized.
void_instance	A void pointer pointing to the instance of the current class.

Returns: Returns with the cost function. (zero if the qubits are desintangled.)

Definition at line 489 of file N_Qubit_Decomposition.cpp.

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◆ optimization_problem_combined()

void N_Qubit_Decomposition::optimization_problem_combined	(	const gsl_vector *	parameters,
		void *	void_instance,
		double *	f0,
		gsl_vector *	grad
	)

static

Call to calculate both the cost function and the its gradient components.

Parameters

parameters	A GNU Scientific Library vector containing the free parameters to be optimized.
void_instance	A void pointer pointing to the instance of the current class.
f0	The value of the cost function at x0.
grad	A GNU Scientific Library vector containing the calculated gradient components.

Definition at line 35 of file Functor_Cost_Function_Gradient.cpp.

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◆ optimization_problem_grad()

void N_Qubit_Decomposition::optimization_problem_grad	(	const gsl_vector *	parameters,
		void *	void_instance,
		gsl_vector *	grad
	)

static

Calculate the approximate derivative (f-f0)/(x-x0) of the cost function with respect to the free parameters.

Parameters

parameters	A GNU Scientific Library vector containing the free parameters to be optimized.
void_instance	A void pointer pointing to the instance of the current class.
grad	A GNU Scientific Library vector containing the calculated gradient components.

Definition at line 17 of file Functor_Cost_Function_Gradient.cpp.

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◆ prepare_operations_to_export() [1/3]

void Decomposition_Base::prepare_operations_to_export ( )

inherited

Call to prepare the optimized operations to export.

The operations are stored in the attribute operations

Definition at line 870 of file Decomposition_Base.cpp.

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◆ prepare_operations_to_export() [2/3]

std::vector< Operation * > Decomposition_Base::prepare_operations_to_export	(	std::vector< Operation * >	ops,
		const double *	parameters
	)

inherited

Call to prepare the optimized operations to export.

Parameters

ops	A list of operations
parameters	The parameters of the operations

Returns: Returns with a list of CNOT and U3 operations.

Definition at line 888 of file Decomposition_Base.cpp.

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◆ prepare_operations_to_export() [3/3]

std::vector< Operation * > Decomposition_Base::prepare_operations_to_export	(	Operation_block *	block_op,
		const double *	parameters
	)

inherited

Call to prepare the operations of an operation block to export.

Parameters

block_op	A pointer to a block of operations
parameters	The parameters of the operations

Returns: Returns with a list of CNOT and U3 operations.

Definition at line 990 of file Decomposition_Base.cpp.

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◆ release_operations()

void Operation_block::release_operations ( )

inherited

Call to release the stored operations.

Definition at line 68 of file Operation_block (copy).cpp.

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◆ reorder_qubits()

void Decomposition_Base::reorder_qubits ( std::vector< int > qbit_list )

virtualinherited

Call to reorder the qubits in the matrix of the operation.

Parameters

qbit_list The reordered list of qubits spanning the matrix

Reimplemented from Operation.

Definition at line 760 of file Decomposition_Base.cpp.

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◆ set_identical_blocks() [1/2]

int N_Qubit_Decomposition::set_identical_blocks	(	int	n,
		int	identical_blocks_in
	)

Set the number of identical successive blocks during the subdecomposition of the n-th qubit.

Parameters

n	The number of qubits for which the maximal number of layers should be used in the subdecomposition.
identical_blocks_in	The number of successive identical layers used in the subdecomposition.

Returns: Returns with zero in case of success.

Definition at line 849 of file N_Qubit_Decomposition.cpp.

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◆ set_identical_blocks() [2/2]

int N_Qubit_Decomposition::set_identical_blocks ( std::map< int, int > identical_blocks_in )

Set the number of identical successive blocks during the subdecomposition of the n-th qubit.

Parameters

identical_blocks_in An <int,int> map containing the number of successive identical layers used in the subdecompositions.

Returns: Returns with zero in case of success.

Definition at line 870 of file N_Qubit_Decomposition.cpp.

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◆ set_iteration_loops() [1/2]

int Decomposition_Base::set_iteration_loops	(	int	n,
		int	iteration_loops_in
	)

inherited

Set the number of iteration loops during the subdecomposition of the n-th qubit.

Parameters

n	The number of qubits for which number of iteration loops should be used in the subdecomposition.,
iteration_loops_in	The number of iteration loops in each sted of the subdecomposition.

Returns: Returns with 0 if succeded.

Definition at line 818 of file Decomposition_Base.cpp.

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◆ set_iteration_loops() [2/2]

int Decomposition_Base::set_iteration_loops ( std::map< int, int > iteration_loops_in )

inherited

Set the number of iteration loops during the subdecomposition of the qbit-th qubit.

Parameters

iteration_loops_in An <int,int> map containing the number of iteration loops for the individual subdecomposition processes

Returns: Returns with 0 if succeded.

Definition at line 838 of file Decomposition_Base.cpp.

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◆ set_matrix()

void Operation::set_matrix ( Matrix input )

inherited

Call to set the stored matrix in the operation.

Parameters

input The operation matrix to be stored. The matrix is stored by attribute matrix_alloc.

Returns: Returns with 0 on success.

Definition at line 109 of file Operation.cpp.

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◆ set_max_iteration()

void Decomposition_Base::set_max_iteration ( int max_iterations_in )

inherited

Call to set the maximal number of the iterations in the optimization process.

Parameters

max_iterations_in maximal number of iteartions in the optimization process

Definition at line 124 of file Decomposition_Base.cpp.

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◆ set_max_layer_num() [1/2]

int Decomposition_Base::set_max_layer_num	(	int	n,
		int	max_layer_num_in
	)

inherited

Set the maximal number of layers used in the subdecomposition of the n-th qubit.

Parameters

n	The number of qubits for which the maximal number of layers should be used in the subdecomposition.
max_layer_num_in	The maximal number of the operation layers used in the subdecomposition.

Returns: Returns with 0 if succeded.

Definition at line 724 of file Decomposition_Base.cpp.

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◆ set_max_layer_num() [2/2]

int Decomposition_Base::set_max_layer_num ( std::map< int, int > max_layer_num_in )

inherited

Set the maximal number of layers used in the subdecomposition of the n-th qubit.

Parameters

max_layer_num_in An <int,int> map containing the maximal number of the operation layers used in the subdecomposition.

Returns: Returns with 0 if succeded.

Definition at line 744 of file Decomposition_Base.cpp.

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◆ set_optimization_blocks()

void Decomposition_Base::set_optimization_blocks ( int optimization_block_in )

inherited

Call to set the number of operation blocks to be optimized in one shot.

Parameters

optimization_block_in The number of operation blocks to be optimized in one shot

Definition at line 116 of file Decomposition_Base.cpp.

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◆ set_qbit_num()

void Operation_block::set_qbit_num ( int qbit_num_in )

virtualinherited

Set the number of qubits spanning the matrix of the operations stored in the block of operations.

Parameters

qbit_num_in The number of qubits spanning the matrices.

Reimplemented from Operation.

Definition at line 633 of file Operation_block (copy).cpp.

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◆ set_verbose()

void Decomposition_Base::set_verbose ( bool verbose_in )

inherited

Call to set the verbose attribute to true or false.

Parameters

verbose_in Logical variable. Set true for verbose mode, or to false to suppress output messages.

Definition at line 1048 of file Decomposition_Base.cpp.

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◆ simplify_layer()

int N_Qubit_Decomposition::simplify_layer	(	Operation_block *	layer,
		double *	parameters,
		unsigned int	parameter_num_block,
		std::map< int, int >	max_layer_num_loc,
		Operation_block *&	simplified_layer,
		double *&	simplified_parameters,
		unsigned int &	simplified_parameter_num
	)

Call to simplify the gate structure in a block of operations (i.e.

tries to reduce the number of CNOT gates)

Parameters

layer	An instance of class Operation_block containing the 2-qubit gate structure to be simplified
parameters	An array of parameters to calculate the matrix representation of the operations in the block of operations.
parameter_num_block	NUmber of parameters in the block of operations to be simplified.
max_layer_num_loc	A map of <int n: int num> indicating the maximal number of CNOT operations allowed in the simplification.
simplified_layer	An instance of Operation_block containing the simplified structure of operations.
simplified_parameters	An array of parameters containing the parameters of the simplified block structure.
simplified_parameter_num	The number of parameters in the simplified block structure.

Returns: Returns with 0 if the simplification wa ssuccessful.

Definition at line 710 of file N_Qubit_Decomposition.cpp.

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◆ simplify_layers()

void N_Qubit_Decomposition::simplify_layers ( )

Call to simplify the gate structure in the layers if possible (i.e.

tries to reduce the number of CNOT gates)

Definition at line 512 of file N_Qubit_Decomposition.cpp.

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◆ solve_layer_optimization_problem()

void N_Qubit_Decomposition::solve_layer_optimization_problem	(	int	num_of_parameters,
		gsl_vector *	solution_guess_gsl
	)

virtual

Call to solve layer by layer the optimization problem.

The optimalized parameters are stored in attribute optimized_parameters.

Parameters

num_of_parameters	Number of parameters to be optimized
solution_guess_gsl	A GNU Scientific Library vector containing the solution guess.

Reimplemented from Decomposition_Base.

Definition at line 373 of file N_Qubit_Decomposition.cpp.

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◆ solve_optimization_problem()

void Decomposition_Base::solve_optimization_problem	(	double *	solution_guess,
		int	solution_guess_num
	)

inherited

This method can be used to solve the main optimization problem which is devidid into sub-layer optimization processes.

(The aim of the optimization problem is to disentangle one or more qubits) The optimalized parameters are stored in attribute optimized_parameters.

Parameters

solution_guess	An array of the guessed parameters
solution_guess_num	The number of guessed parameters. (not necessarily equal to the number of free parameters)

Definition at line 283 of file Decomposition_Base.cpp.

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◆ start_decomposition()

void N_Qubit_Decomposition::start_decomposition	(	bool	finalize_decomp = `true`,
		bool	prepare_export = `true`
	)

Start the disentanglig process of the unitary.

Parameters

finalize_decomp	Optional logical parameter. If true (default), the decoupled qubits are rotated into state \|0> when the disentangling of the qubits is done. Set to False to omit this procedure
prepare_export	Logical parameter. Set true to prepare the list of operations to be exported, or false otherwise.

Definition at line 76 of file N_Qubit_Decomposition.cpp.

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Member Data Documentation

◆ control_qbit

int Operation::control_qbit

protectedinherited

The index of the qubit which acts as a control qubit (control_qbit >= 0) in controlled operations.

Definition at line 52 of file Operation.h.

◆ current_minimum

double Decomposition_Base::current_minimum

protectedinherited

The current minimum of the optimization problem.

Definition at line 90 of file Decomposition_Base.h.

◆ decomposition_error

double Decomposition_Base::decomposition_error

protectedinherited

error of the unitarity of the final decomposition

Definition at line 81 of file Decomposition_Base.h.

◆ decomposition_finalized

bool Decomposition_Base::decomposition_finalized

protectedinherited

logical value describing whether the decomposition was finalized or not (i.e. whether the decomposed qubits were rotated into the state |0> or not)

Definition at line 78 of file Decomposition_Base.h.

◆ finalizing_operations_num

int Decomposition_Base::finalizing_operations_num

protectedinherited

number of finalizing (deterministic) opertaions rotating the disentangled qubits into state |0>.

Definition at line 84 of file Decomposition_Base.h.

◆ finalizing_parameter_num

int Decomposition_Base::finalizing_parameter_num

protectedinherited

the number of the finalizing (deterministic) parameters of operations rotating the disentangled qubits into state |0>.

Definition at line 87 of file Decomposition_Base.h.

◆ global_target_minimum

double Decomposition_Base::global_target_minimum

protectedinherited

The global target minimum of the optimization problem.

Definition at line 93 of file Decomposition_Base.h.

◆ identical_blocks

std::map<int,int> N_Qubit_Decomposition::identical_blocks

protected

A map of <int n: int num> indicating that how many identical succesive blocks should be used in the disentanglement of the nth qubit from the others.

Definition at line 48 of file N_Qubit_Decomposition.h.

◆ initial_guess

guess_type Decomposition_Base::initial_guess

protectedinherited

type to guess the initial values for the optimization. Possible values: ZEROS=0, RANDOM=1, CLOSE_TO_ZERO=2

Definition at line 102 of file Decomposition_Base.h.

◆ iteration_loops

std::map<int,int> Decomposition_Base::iteration_loops

protectedinherited

A map of <int n: int num> indicating the number of iteration in each step of the decomposition.

Definition at line 69 of file Decomposition_Base.h.

◆ layer_num

int Operation_block::layer_num

protectedinherited

number of operation layers

Definition at line 43 of file Operation_block.h.

◆ matrix_size

int Operation::matrix_size

protectedinherited

The size N of the NxN matrix associated with the operations.

Definition at line 54 of file Operation.h.

◆ max_iterations

int Decomposition_Base::max_iterations

protectedinherited

Maximal number of iterations allowed in the optimization process.

Definition at line 99 of file Decomposition_Base.h.

◆ max_layer_num

std::map<int,int> Decomposition_Base::max_layer_num

protectedinherited

A map of <int n: int num> indicating that how many layers should be used in the subdecomposition process for the subdecomposing of the nth qubits.

Definition at line 66 of file Decomposition_Base.h.

◆ max_layer_num_def

std::map< int, int > Decomposition_Base::max_layer_num_def

staticinherited

A map of <int n: int num> indicating that how many layers should be used in the subdecomposition process by default for the subdecomposing of the nth qubits.

Definition at line 58 of file Decomposition_Base.h.

◆ num_threads

int Decomposition_Base::num_threads

protectedinherited

Number of outer OpenMP threads. (During the calculations OpenMP multithreading is turned off.)

Definition at line 105 of file Decomposition_Base.h.

◆ operations

std::vector<Operation*> Operation_block::operations

protectedinherited

The list of stored operations.

Definition at line 41 of file Operation_block.h.

◆ optimization_block

int Decomposition_Base::optimization_block

inherited

number of operation blocks used in one shot of the optimization process

Definition at line 55 of file Decomposition_Base.h.

◆ optimization_problem_solved

bool Decomposition_Base::optimization_problem_solved

protectedinherited

logical value describing whether the optimization problem was solved or not

Definition at line 96 of file Decomposition_Base.h.

◆ optimization_tolerance

double Decomposition_Base::optimization_tolerance

inherited

The maximal allowed error of the optimization problem.

Definition at line 61 of file Decomposition_Base.h.

◆ optimize_layer_num

bool N_Qubit_Decomposition::optimize_layer_num

protected

logical value. Set true to optimize the minimum number of operation layers required in the decomposition, or false when the predefined maximal number of layer gates is used (ideal for general unitaries).

Definition at line 45 of file N_Qubit_Decomposition.h.

◆ optimized_parameters

double* Decomposition_Base::optimized_parameters

protectedinherited

The optimized parameters for the operations.

Definition at line 75 of file Decomposition_Base.h.

◆ parameter_num

unsigned int Operation::parameter_num

protectedinherited

the number of free parameters of the operation

Definition at line 56 of file Operation.h.

◆ qbit_num

int Operation::qbit_num

protectedinherited

number of qubits spanning the matrix of the operation

Definition at line 46 of file Operation.h.

◆ target_qbit

int Operation::target_qbit

protectedinherited

The index of the qubit on which the operation acts (target_qbit >= 0)

Definition at line 50 of file Operation.h.

◆ type

operation_type Operation::type

protectedinherited

The type of the operation (see enumeration operation_type)

Definition at line 48 of file Operation.h.

◆ Umtx

Matrix Decomposition_Base::Umtx

protectedinherited

The unitary to be decomposed.

Definition at line 72 of file Decomposition_Base.h.

◆ verbose

bool Decomposition_Base::verbose

inherited

Logical variable. Set true for verbose mode, or to false to suppress output messages.

Definition at line 52 of file Decomposition_Base.h.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ N_Qubit_Decomposition()

◆ ~N_Qubit_Decomposition()

Member Function Documentation

◆ add_cnot_to_end()

◆ add_cnot_to_front()

◆ add_operation_to_end()

◆ add_operation_to_front()

◆ add_operations_to_end()

◆ add_operations_to_front()

◆ add_u3_to_end()

◆ add_u3_to_front()

◆ apply_operation()

◆ check_optimization_solution()

◆ clone()

◆ combine()

◆ decompose_submatrix()

◆ extract_operations()

◆ extract_subdecomposition_results()

◆ final_optimization()

◆ finalize_decomposition()

◆ get_control_qbit()

◆ get_decomposed_matrix()

◆ get_decomposition_error()

◆ get_finalizing_operations()

◆ get_gate_nums()

◆ get_involved_qubits()

◆ get_matrices()

◆ get_matrix() [1/2]

◆ get_matrix() [2/2]

◆ get_operation()

◆ get_operation_num()

◆ get_operation_products()

◆ get_operations()

◆ get_optimized_parameters() [1/2]

◆ get_optimized_parameters() [2/2]

◆ get_parameter_num()

◆ get_qbit_num()

◆ get_target_qbit()

◆ get_transformed_matrix() [1/2]

◆ get_transformed_matrix() [2/2]

◆ get_type()

◆ get_Umtx()

◆ get_Umtx_size()

◆ Init_max_layer_num()

◆ list_operations() [1/2]

◆ list_operations() [2/2]

◆ optimization_problem() [1/2]

◆ optimization_problem() [2/2]

◆ optimization_problem_combined()

◆ optimization_problem_grad()

◆ prepare_operations_to_export() [1/3]

◆ prepare_operations_to_export() [2/3]

◆ prepare_operations_to_export() [3/3]

◆ release_operations()

◆ reorder_qubits()

◆ set_identical_blocks() [1/2]

◆ set_identical_blocks() [2/2]

◆ set_iteration_loops() [1/2]

◆ set_iteration_loops() [2/2]

◆ set_matrix()

◆ set_max_iteration()

◆ set_max_layer_num() [1/2]

◆ set_max_layer_num() [2/2]

◆ set_optimization_blocks()

◆ set_qbit_num()

◆ set_verbose()

◆ simplify_layer()

◆ simplify_layers()

◆ solve_layer_optimization_problem()

◆ solve_optimization_problem()

◆ start_decomposition()

Member Data Documentation

◆ control_qbit