IterativeCommuteAndMerge

IterativeCommuteAndMerge#

class pennylane_calculquebec.processing.steps.optimization.IterativeCommuteAndMerge#

Bases: Optimize

Decomposes iteratively until the circuit contains only rotations. For each decomposition step, applies commutations, merges and cancellations

HCZH_cnot(wires)

Decomposition for a cnot using CZ and H

Y_to_ZXZ(operation)

Turn RY into RZ, RX and RZ

ZXZ_Hadamard(wires)

Turns H into a combination of S, SX and S

execute(tape)

decomposes swaps, cnots and hadamards iteratively.

get_rid_of_y_rotations(tape)

Transforms all Y rotations in a tape to X and Z rotations

swap_cnot(wires)

turns swaps into cnots
static HCZH_cnot(wires)#

Decomposition for a cnot using CZ and H

Parameters:

wires (WireLike) – Which wires should we decompose with?

Raises:

ValueError – There should be exactly two wires

Returns:

the list of operations corresponding to a CNOT using CZ and H

Return type:

list[Operation]

static Y_to_ZXZ(operation)#

Turn RY into RZ, RX and RZ

Parameters:

operation (Operation) – a RY gate with arbitrary angle

Raises:

  • ValueError – There should be exactly one wire

  • ValueError – The gate should be in the Y basis

Returns:

The equivalent sequence of X/Z gates for an arbitrary Y rotation

Return type:

list[Operation]

static ZXZ_Hadamard(wires)#

Turns H into a combination of S, SX and S

Parameters:

wires (WireLike) – What wires should we decompose with?

Raises:

ValueError – There should be exactly one wire

Returns:

a list of operations corresponding to H

Return type:

list[Operation]

execute(tape)#

decomposes swaps, cnots and hadamards iteratively. Then turns everything to Z and X rotations.

at each iteration, apply commutations, rotation merges, and trivial and inverse gates cancellations

Parameters:

tape (QuantumTape) – the tape to optimize

Returns:

an optimized QuantumTape

Return type:

QuantumTape

static get_rid_of_y_rotations(tape: QuantumTape)#

Transforms all Y rotations in a tape to X and Z rotations

Parameters:

tape (QuantumTape) – the tape to act on

Returns:

the processed tape

Return type:

QuantumTape

static swap_cnot(wires)#

turns swaps into cnots

Parameters:

wires (WireLike) – which wires do the swap act on

Returns:

cnot(a, b) cnot(b, a) cnot(a, b)

Return type:

list[Operation]