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# Copyright © 2022-2023 University of Strasbourg. All Rights Reserved.
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# Licensed under the Apache License, Version 2.0 (the "License");
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import mimiqcircuits.operations.gates.gate as mcg
from mimiqcircuits.operations.gates.standard.cpauli import GateCX
from mimiqcircuits.operations.utils import power_idempotent, control_one_defined
import mimiqcircuits as mc
from symengine import Matrix
[docs]
class GateSWAP(mcg.Gate):
r"""Two qubit SWAP gate.
See Also :func:`GateISWAP`
**Matrix representation:**
.. math::
\operatorname{SWAP} = \begin{pmatrix}
1 & 0 & 0 & 0 \\
0 & 0 & 1 & 0 \\
0 & 1 & 0 & 0 \\
0 & 0 & 0 & 1
\end{pmatrix}
Examples:
>>> from mimiqcircuits import *
>>> GateSWAP()
SWAP
>>> GateSWAP().matrix()
[1.0, 0, 0, 0]
[0, 0, 1.0, 0]
[0, 1.0, 0, 0]
[0, 0, 0, 1.0]
<BLANKLINE>
>>> c = Circuit().push(GateSWAP(), 0, 1)
>>> GateSWAP().power(2), GateSWAP().inverse()
(Parallel(2, ID), SWAP)
>>> GateSWAP().decompose()
2-qubit circuit with 3 instructions:
├── CX @ q[0], q[1]
├── CX @ q[1], q[0]
└── CX @ q[0], q[1]
<BLANKLINE>
"""
_name = "SWAP"
_num_qubits = 2
_qregsizes = [2]
def _matrix(self):
return Matrix([[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0], [0, 0, 0, 1]])
[docs]
def inverse(self):
return self
def _power(self, p):
# SWAP^(2n) = ID
# SWAP^(2n + 1) = SWAP
return power_idempotent(self, p)
def _control(self, n):
return control_one_defined(n, self, mc.GateCSWAP())
def _decompose(self, circ, qubits, bits):
c, t = qubits
circ.push(GateCX(), c, t)
circ.push(GateCX(), t, c)
circ.push(GateCX(), c, t)
return circ
