qiskit.circuit.library.SwapGate
class SwapGate(label=None)
The SWAP gate.
This is a symmetric and Clifford gate.
Circuit symbol:
q_0: ─X─
│
q_1: ─X─
Matrix Representation:
The gate is equivalent to a state swap and is a classical logic gate.
Create new SWAP gate.
__init__
__init__(label=None)
Create new SWAP gate.
Methods
__init__ ([label]) | Create new SWAP gate. |
add_decomposition (decomposition) | Add a decomposition of the instruction to the SessionEquivalenceLibrary. |
assemble () | Assemble a QasmQobjInstruction |
broadcast_arguments (qargs, cargs) | Validation and handling of the arguments and its relationship. |
c_if (classical, val) | Add classical condition on register classical and value val. |
control ([num_ctrl_qubits, label, ctrl_state]) | Return a (multi-)controlled-SWAP gate. |
copy ([name]) | Copy of the instruction. |
inverse () | Return inverse Swap gate (itself). |
is_parameterized () | Return True .IFF. |
mirror () | DEPRECATED: use instruction.reverse_ops(). |
power (exponent) | Creates a unitary gate as gate^exponent. |
qasm () | Return a default OpenQASM string for the instruction. |
repeat (n) | Creates an instruction with gate repeated n amount of times. |
reverse_ops () | For a composite instruction, reverse the order of sub-instructions. |
to_matrix () | Return a numpy.array for the SWAP gate. |
validate_parameter (parameter) | Gate parameters should be int, float, or ParameterExpression |
Attributes
decompositions | Get the decompositions of the instruction from the SessionEquivalenceLibrary. |
definition | Return definition in terms of other basic gates. |
duration | Get the duration. |
label | Return gate label |
params | return instruction params. |
unit | Get the time unit of duration. |
add_decomposition
add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
assemble
assemble()
Assemble a QasmQobjInstruction
Return type
Instruction
broadcast_arguments
broadcast_arguments(qargs, cargs)
Validation and handling of the arguments and its relationship.
For example, cx([q[0],q[1]], q[2])
means cx(q[0], q[2]); cx(q[1], q[2])
. This method yields the arguments in the right grouping. In the given example:
in: [[q[0],q[1]], q[2]],[]
outs: [q[0], q[2]], []
[q[1], q[2]], []
The general broadcasting rules are:
If len(qargs) == 1:
[q[0], q[1]] -> [q[0]],[q[1]]
If len(qargs) == 2:
[[q[0], q[1]], [r[0], r[1]]] -> [q[0], r[0]], [q[1], r[1]] [[q[0]], [r[0], r[1]]] -> [q[0], r[0]], [q[0], r[1]] [[q[0], q[1]], [r[0]]] -> [q[0], r[0]], [q[1], r[0]]
If len(qargs) >= 3:
[q[0], q[1]], [r[0], r[1]], ...] -> [q[0], r[0], ...], [q[1], r[1], ...]
Parameters
- qargs (
List
) – List of quantum bit arguments. - cargs (
List
) – List of classical bit arguments.
Return type
Tuple
[List
, List
]
Returns
A tuple with single arguments.
Raises
CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.
c_if
c_if(classical, val)
Add classical condition on register classical and value val.
control
control(num_ctrl_qubits=1, label=None, ctrl_state=None)
Return a (multi-)controlled-SWAP gate.
One control returns a CSWAP (Fredkin) gate.
Parameters
- num_ctrl_qubits (int) – number of control qubits.
- label (str or None) – An optional label for the gate [Default: None]
- ctrl_state (int or str or None) – control state expressed as integer, string (e.g. ‘110’), or None. If None, use all 1s.
Returns
controlled version of this gate.
Return type
copy
copy(name=None)
Copy of the instruction.
Parameters
name (str) – name to be given to the copied circuit, if None then the name stays the same.
Returns
a copy of the current instruction, with the name
updated if it was provided
Return type
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
Return definition in terms of other basic gates.
duration
Get the duration.
inverse
inverse()
Return inverse Swap gate (itself).
is_parameterized
is_parameterized()
Return True .IFF. instruction is parameterized else False
label
Return gate label
Return type
str
mirror
mirror()
DEPRECATED: use instruction.reverse_ops().
Returns
a new instruction with sub-instructions
reversed.
Return type
params
return instruction params.
power
power(exponent)
Creates a unitary gate as gate^exponent.
Parameters
exponent (float) – Gate^exponent
Returns
To which to_matrix is self.to_matrix^exponent.
Return type
Raises
CircuitError – If Gate is not unitary
qasm
qasm()
Return a default OpenQASM string for the instruction.
Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).
repeat
repeat(n)
Creates an instruction with gate repeated n amount of times.
Parameters
n (int) – Number of times to repeat the instruction
Returns
Containing the definition.
Return type
Raises
CircuitError – If n < 1.
reverse_ops
reverse_ops()
For a composite instruction, reverse the order of sub-instructions.
This is done by recursively reversing all sub-instructions. It does not invert any gate.
Returns
a new instruction with
sub-instructions reversed.
Return type
to_matrix
to_matrix()
Return a numpy.array for the SWAP gate.
unit
Get the time unit of duration.
validate_parameter
validate_parameter(parameter)
Gate parameters should be int, float, or ParameterExpression