openql¶

OpenQL is a C++/Python framework for high-level quantum programming. The framework provides a compiler for compiling and optimizing quantum code. The compiler produces the intermediate quantum assembly language in cQASM (Common QASM) and the compiled eQASM (executable QASM) for various target platforms. While the eQASM is platform-specific, the quantum assembly code (QASM) is hardware-agnostic and can be simulated on the QX simulator.

Functions

`get_option`(option_name)	Returns value of any of the following OpenQL options:
`get_version`()	Returns OpenQL version
`print_options`()	Prints a list of available OpenQL options with their values.
`set_option`(option_name, option_value)	Sets any of the following OpenQL options:

Classes

`CReg`()	Classical register class.
`Kernel`(*args)	Kernel class which contains various quantum instructions.
`Operation`(*args)	Operation class representing classical operations.
`Platform`(*args)	Platform class specifying the target platform to be used for compilation.
`Program`(*args)	Program class which contains one or more kernels.
`Compiler`(name)	Compiler class which contains one or more compiler passes.

class openql.openql.CReg: Classical register class.

class openql.openql.Compiler(name)

Compiler class which contains one or more compiler passes.

add_pass(realPassName)

Adds a compiler pass under its real name

Parameters:	arg1 (str) – name of the real pass to be added.

add_pass_alias(realPassName, symbolicPassName)

Adds a compiler pass under an alias name

Parameters:	arg1 (str) – name of the real pass to be added. arg2 (str) – alias name of the pass to be added.

compile(program)

Compiles the program

Parameters:	arg1 (Program) – program object to be compiled.

set_pass_option(passName, optionName, optionValue)

Sets a compiler pass option

Parameters:	arg1 (str) – name (real or alias) of the compiler pass to be added. arg2 (str) – option name of the option to be configured. arg3 (str) – value of the option.

class openql.openql.Kernel(*args)

Kernel class which contains various quantum instructions.

barrier(*args)

inserts explicit barrier on specified qubits.

wait with duration ‘0’ is also equivalent to applying barrier on specified list of qubits. If no qubits are specified, then barrier is applied on all the qubits.

Parameters:	arg1 ([]) – list of qubits

classical(*args)

adds classical operation kernel.

Parameters:	arg1 (CReg) – destination register for classical operation. arg2 (Operation) – classical operation.

clifford(id, q0)

Applies clifford operation of the specified id on the qubit.

The ids and the corresponding operations are:

id	Operations
0	[‘I’]
1	[‘Y90’, ‘X90’]
2	[‘mX90’, ‘mY90’]
3	[‘X180’]
4	[‘mY90’, ‘mX90’]
5	[‘X90’, ‘mY90’]
6	[‘Y180’]
7	[‘mY90’, ‘X90’]
8	[‘X90’, ‘Y90’]
9	[‘X180’, ‘Y180’]
10	[‘Y90’, ‘mX90’]
11	[‘mX90’, ‘Y90’]
12	[‘Y90’, ‘X180’]
13	[‘mX90’]
14	[‘X90’, ‘mY90’, ‘mX90’]
15	[‘mY90’]
16	[‘X90’]
17	[‘X90’, ‘Y90’, ‘X90’]
18	[‘mY90’, ‘X180’]
19	[‘X90’, ‘Y180’]
20	[‘X90’, ‘mY90’, ‘X90’]
21	[‘Y90’]
22	[‘mX90’, ‘Y180’]
23	[‘X90’, ‘Y90’, ‘mX90’]

Parameters:	arg1 (int) – clifford operation id arg2 (int) – target qubit

cnot(q0, q1)

Applies controlled-not operation.

Parameters:	arg1 (int) – control qubit arg2 (int) – target qubit

conjugate(k)

generates conjugate version of the kernel from the input kernel.

Parameters:	arg1 (ql::Kernel) – input kernel. Except measure, Kernel to be conjugated.
Returns:
Return type:	None

controlled(k, control_qubits, ancilla_qubits)

generates controlled version of the kernel from the input kernel.

Parameters:	arg1 (ql::Kernel) – input kernel. Except measure, Kernel to be controlled may contain any of the default gates as well custom gates which are not specialized for a specific qubits. arg2 ([]) – list of control qubits. arg3 ([]) – list of ancilla qubits. Number of ancilla qubits should be equal to number of control qubits.
Returns:
Return type:	None

cphase(q0, q1)

Applies controlled-phase operation.

Parameters:	arg1 (int) – control qubit arg2 (int) – target qubit

display()

inserts QX display instruction (so QX specific).

Parameters:	None –
Returns:
Return type:	None

gate(*args)

adds unitary to kernel.

Parameters:	arg1 (Unitary) – unitary matrix arg2 ([]) – list of qubits

get_custom_instructions()

Returns list of available custom instructions.

Parameters:	None –
Returns:	List of available custom instructions
Return type:	[]

hadamard(q0)

Applies hadamard on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

identity(q0)

Applies identity on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

measure(q0)

measures input qubit.

Parameters:	arg1 (int) – input qubit

mrx90(q0)

Applies mrx90 on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

rx180(q0)

Applies rx180 on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

rx90(q0)

Applies rx90 on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

ry180(q0)

Applies ry180 on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

s(q0)

Applies x on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

sdag(q0)

Applies sdag on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

toffoli(q0, q1, q2)

Applies controlled-controlled-not operation.

Parameters:	arg1 (int) – control qubit arg2 (int) – control qubit arg3 (int) – target qubit

wait(qubits, duration)

inserts explicit wait of specified duration on specified qubits.

wait with duration ‘0’ is equivalent to barrier on specified list of qubits. If no qubits are specified, then wait/barrier is applied on all the qubits.

Parameters:	arg1 ([]) – list of qubits arg2 (int) – duration in ns

y(q0)

Applies y on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

z(q0)

Applies z on the qubit specified in argument.

Parameters:	arg1 (int) – target qubit

class openql.openql.Operation(*args): Operation class representing classical operations.

class openql.openql.Platform(*args)

Platform class specifying the target platform to be used for compilation.

get_qubit_number()

returns number of qubits in the platform.

Parameters:	None –
Returns:	number of qubits
Return type:	int

class openql.openql.Program(*args)

Program class which contains one or more kernels.

add_do_while(*args)

Adds specified sub-program to a program which will be repeatedly executed while specified condition is true.

Parameters:	arg1 (Program) – program to be executed repeatedly arg2 (Operation) – classical relational operation (<, >, <=, >=, ==, !=)

add_for(*args)

Adds specified sub-program to a program which will be executed for specified iterations.

Parameters:	arg1 (Program) – sub-program to be executed repeatedly arg2 (int) – iteration count

add_if(*args)

Adds specified sub-program to a program which will be executed if specified condition is true. This allows nesting of operations.

Parameters:	arg1 (Program) – program to be executed arg2 (Operation) – classical relational operation (<, >, <=, >=, ==, !=)

add_if_else(*args)

Adds specified sub-programs to a program. First sub-program will be executed if specified condition is true. Second sub-program will be executed if specified condition is false.

Parameters:	arg1 (Program) – program to be executed when specified condition is true (if part). arg2 (Program) – program to be executed when specified condition is false (else part). arg3 (Operation) – classical relational operation (<, >, <=, >=, ==, !=)

add_kernel(k)

Adds specified kernel to program.

Parameters:	arg1 (kernel) – kernel to be added

compile()

Compiles the program

Parameters:	None –

get_sweep_points()

Returns sweep points for an experiment.

Parameters:	None –
Returns:	list of sweep points
Return type:	[]

microcode()

Returns program microcode

Parameters:	None –
Returns:	microcode
Return type:	str

set_sweep_points(sweep_points)

Sets sweep points for an experiment.

Parameters:	arg1 ([]) – list of sweep points

class openql.openql.Unitary(name, matrix)

Unitary class to hold the matrix and its decomposition

decompose()

Decomposes the unitary matrix

Parameters:	None –
Returns:
Return type:	None

class openql.openql.cQasmReader(q_platform, q_program)

cQasmReader class specifies an interface to add cqasm programs to a program.

file2circuit(cqasm_file_path)

Adds a cqasm program read from a file.

Parameters:	arg1 (str) – File path to the file specifying the cqasm that is added to the program.

string2circuit(cqasm_str)

Adds a cqasm program defined in a string.

Parameters:	arg1 (str) – The cqasm that is added to the program.

openql.openql.get_option(option_name)

Returns value of any of the following OpenQL options:

Opt. Name	Defaults	Possible values
log_level	LOG_NOTHING	LOG_{NOTHING/CRITICAL/ERROR/WARNING/INFO/DEBUG}
output_dir	test_output	<output directory>
optimize	no	yes/no
use_default_gates	yes	yes/no
decompose_toffoli	no	yes/no
scheduler	ASAP	ASAP/ALAP
scheduler_uniform	no	yes/no
scheduler_commute	no	yes/no
scheduler_post179	yes	yes/no
cz_mode	manual	auto/manual

Parameters:	arg1 (str) – Option name
Returns:	Option value
Return type:	str

openql.openql.get_version()

Returns OpenQL version

Parameters:	None –
Returns:	version number as a string
Return type:	str

openql.openql.print_options(): Prints a list of available OpenQL options with their values.

openql.openql.set_option(option_name, option_value)

Sets any of the following OpenQL options:

Opt. Name	Defaults	Possible values
log_level	LOG_NOTHING	LOG_{NOTHING/CRITICAL/ERROR/WARNING/INFO/DEBUG}
output_dir	test_output	<output directory>
optimize	no	yes/no
use_default_gates	yes	yes/no
decompose_toffoli	no	yes/no
scheduler	ASAP	ASAP/ALAP
scheduler_uniform	no	yes/no
scheduler_commute	no	yes/no
scheduler_post179	yes	yes/no
cz_mode	manual	auto/manual

Parameters:	arg1 (str) – Option name arg2 (str) – Option value