mimiqcircuits.decomposition.basis.qasm¶

OpenQASM 2.0 decomposition basis.

Classes

QASMBasis()

Decomposition basis targeting the OpenQASM 2.0 gate library.

class mimiqcircuits.decomposition.basis.qasm.QASMBasis[source]¶

Bases: DecompositionBasis

Decomposition basis targeting the OpenQASM 2.0 gate library.

The terminal gates are the OpenQASM 2.0 built-ins and the gates of the qelib1.inc include file that have a direct MIMIQ counterpart, so a decomposed circuit can be written as OpenQASM 2.0 and read back by any parser that ships the standard qelib1.inc.

Terminal Operations¶

Fundamental gates (OpenQASM 2.0 built-in):

GateU, GateCX

Single-qubit gates from qelib1.inc:

Legacy U gates: GateU3, GateU2, GateU1
Pauli: GateID, GateX, GateY, GateZ
Hadamard: GateH
Phase: GateS, GateSDG, GateT, GateTDG
Rotations: GateRX, GateRY, GateRZ

Two-qubit gates from qelib1.inc:

Controlled Paulis and Hadamard: GateCY, GateCZ, GateCH
Controlled rotations: GateCRX, GateCRY, GateCRZ
GateSWAP
Ising couplings: GateRXX, GateRZZ

Three- and four-qubit gates from qelib1.inc:

GateCCX, GateCSWAP, GateC3X

Non-unitary operations:

Measure, Reset, Barrier
IfStatement whose inner operation is terminal

Custom gates:

GateCall whose declaration contains only terminal operations

Every other operation is decomposed through CanonicalRewrite. Operations that OpenQASM 2.0 cannot express and that have no decomposition into the gates above (noise channels, classical operations, annotations, Z-register operations, …) raise DecompositionError.

MeasureReset decomposes into Measure followed by Reset. This leaves the same state and bit as its canonical decomposition, a measurement and an X conditioned on its outcome, and unlike that conditional it can be written for a circuit of any number of bits. OpenQASM 2.0 has no loops, so WhileStatement raises DecompositionError.

Example

>>> from mimiqcircuits import Circuit, GateH, GateCCX
>>> from mimiqcircuits.decomposition import decompose, QASMBasis
>>> c = Circuit()
>>> c.push(GateH(), 0)
1-qubit circuit with 1 instruction:
└── H @ q[0]

>>> c.push(GateCCX(), 0, 1, 2)
3-qubit circuit with 2 instructions:
├── H @ q[0]
└── C₂X @ q[0:1], q[2]

>>> # Decompose to QASM-compatible gates
>>> qasm_circuit = decompose(c, QASMBasis())