cirq_superstaq.ops.qubit_gates

Miscellaneous custom gates that we encounter and want to explicitly define.

Attributes

`AQTICCX`
`AQTITOFFOLI`
`AceCRMinusPlus`
`AceCRPlusMinus`
`CR`
`DD`
`ICCX`
`IX`
`ZX`

Classes

`AceCR`	Active Cancellation Echoed Cross Resonance (AceCR) gate, parametrized (e.g., supporting
`Barrier`	A temporal boundary restricting circuit compilation and pulse scheduling.
`DDPowGate`	The Dipole-Dipole gate for EeroQ hardware.
`IXGate`	Thin wrapper of \(RX(-\pi)\) to improve iToffoli circuit diagrams.
`ParallelGates`	A single gate combining a collection of concurrent gate(s) acting on different qubits.
`ParallelRGate`	Wrapper class to define a ParallelGate of identical RGate gates.
`RGate`	A single-qubit gate that rotates about an axis in the X-Y plane.
`StrippedCZGate`	The Stripped CZ gate is a regular CZ gate when the rz angle = 0.
`ZXPowGate`	The ZX-parity gate, possibly raised to a power.
`ZZSwapGate`	The ZZ-SWAP gate, which performs the ZZ-interaction followed by a SWAP.

Functions

`approx_eq_mod`(→ bool)	Check if a ~= b (mod period). If either input is an unresolved parameter, returns a == b.
`barrier`(→ cirq.Operation)	Equivalent to https://qiskit.org/documentation/stubs/qiskit.circuit.library.Barrier.html.
`custom_resolver`(→ type[cirq.Gate] \| None)	Tells cirq.read_json how to deserialize cirq-superstaq's custom gates.
`parallel_gates_operation`(→ cirq.Operation)	Constructs a parallel gates operation.

Module Contents

class cirq_superstaq.ops.qubit_gates.AceCR(rads: str | cirq.TParamVal = np.pi / 2, sandwich_rx_rads: cirq.TParamVal = 0)

Bases: cirq.Gate

Active Cancellation Echoed Cross Resonance (AceCR) gate, parametrized (e.g., supporting polarity switches) and supporting sandwiches.

The typical AceCR in literature is a positive half-CR, then X on “Z side”, then negative half-CR (“Z side” and “X side” refer to the two sides of the underlying ZX interactions).

rads

sandwich_rx_rads = 0

class cirq_superstaq.ops.qubit_gates.Barrier(num_qubits: int | None = None, qid_shape: Tuple[int, Ellipsis] | None = None)

Bases: cirq.ops.IdentityGate, cirq.InterchangeableQubitsGate

A temporal boundary restricting circuit compilation and pulse scheduling.

Otherwise equivalent to the identity gate.

class cirq_superstaq.ops.qubit_gates.DDPowGate(*, exponent: cirq.value.TParamVal = 1.0, global_shift: float = 0.0)

Bases: cirq.EigenGate

The Dipole-Dipole gate for EeroQ hardware.

class cirq_superstaq.ops.qubit_gates.IXGate

Bases: cirq.XPowGate

Thin wrapper of \(RX(-\pi)\) to improve iToffoli circuit diagrams.

class cirq_superstaq.ops.qubit_gates.ParallelGates(*component_gates: cirq.Gate)

Bases: cirq.Gate, cirq.InterchangeableQubitsGate

A single gate combining a collection of concurrent gate(s) acting on different qubits.

qubit_index_to_equivalence_group_key(index: int) → int

Returns a key that differs between qubits.

Does it by different component gates and non-interchangeable qubits in the same component gate.

Parameters:: index – The qubit index.
Returns:: Equivalence group key.

qubit_index_to_gate_and_index(index: int) → tuple[cirq.Gate, int]

Gets gate (and index) for the corresponding index.

Parameters:: index – The index into a particular member of the ParallelGates operation.
Returns:: A tuple of the gate at the given index and the index itself.
Raises:: ValueError – If index is outside bounds of gate index range.

component_gates: tuple[cirq.Gate, Ellipsis] = ()

class cirq_superstaq.ops.qubit_gates.ParallelRGate(theta: cirq.TParamVal, phi: cirq.TParamVal, num_copies: int)

Bases: cirq.ParallelGate, cirq.InterchangeableQubitsGate

Wrapper class to define a ParallelGate of identical RGate gates.

property exponent: cirq.TParamVal

The exponent property of ParallelRGate.

Returns:: The sub gate exponent.

property phase_exponent: cirq.TParamVal

The phase_exponent property of each RGate.

Returns:: The phase exponent.

property phi: cirq.TParamVal

The phi property of ParallelRGate, defining orientation (i.e., axis of rotation).

Returns:: The rotation-axis angle phi.

property sub_gate: RGate

The gate that is applied to the specified subspace.

Returns:: The underlying gate used.

property theta: cirq.TParamVal

The theta property of ParallelRGate, angle to rotate about the phi-determined axis.

Returns:: The rotation angle theta.

class cirq_superstaq.ops.qubit_gates.RGate(theta: cirq.TParamVal, phi: cirq.TParamVal)

Bases: cirq.PhasedXPowGate

A single-qubit gate that rotates about an axis in the X-Y plane.

property phi: cirq.TParamVal

Angle (in radians) defining the axis of rotation in the X-Y plane.

Returns:: The phi rotation angle.

property theta: cirq.TParamVal

Angle (in radians) by which to rotate about the axis given by self.phi.

Returns:: The theta rotation angle.

class cirq_superstaq.ops.qubit_gates.StrippedCZGate(rz_rads: cirq.TParamVal = 0)

Bases: cirq.Gate

The Stripped CZ gate is a regular CZ gate when the rz angle = 0.

It is the gate that is actually being performed by Sqale, and it is corrected into a CZ gate by RZ gates afterwards if the rz angle is nonzero.

property rz_rads: cirq.TParamVal

The RZ-rotation angle in radians for the gate.

Returns:: The angle for the RZ rotation.

class cirq_superstaq.ops.qubit_gates.ZXPowGate(*, exponent: cirq.value.TParamVal = 1.0, global_shift: float = 0.0)

Bases: cirq.EigenGate

The ZX-parity gate, possibly raised to a power.

Per arxiv.org/pdf/1904.06560v3 eq. 135, the ZX**t gate implements the following unitary:

\[\begin{split}e^{-\frac{i\pi}{2} t Z \otimes X} = \begin{bmatrix} c & -s & . & . \\ -s & c & . & . \\ . & . & c & s \\ . & . & s & c \\ \end{bmatrix}\end{split}\]

where ‘.’ means ‘0’ and \(c = \cos(\frac{\pi t}{2})\) and \(s = i \sin(\frac{\pi t}{2})\).

class cirq_superstaq.ops.qubit_gates.ZZSwapGate(theta: cirq.TParamVal)

Bases: cirq.Gate, cirq.ops.gate_features.InterchangeableQubitsGate

The ZZ-SWAP gate, which performs the ZZ-interaction followed by a SWAP.

ZZ-SWAPs are useful for applications like QAOA or Hamiltonian Simulation, particularly on linear- or low- connectivity devices. See https://arxiv.org/pdf/2004.14970.pdf for an application of ZZ SWAP networks.

The unitary for a ZZ-SWAP gate parametrized by ZZ-interaction angle \(\theta\) is:

\[\begin{split}\begin{bmatrix} 1 & . & . & . \\ . & . & e^{i \theta} & . \\ . & e^{i \theta} & . & . \\ . & . & . & 1 \\ \end{bmatrix}\end{split}\]

where ‘.’ means ‘0’. For \(\theta = 0\), the ZZ-SWAP gate is just an ordinary SWAP.

theta

cirq_superstaq.ops.qubit_gates.approx_eq_mod(a: cirq.TParamVal, b: cirq.TParamVal, period: float, atol: float = 1e-08) → bool

Check if a ~= b (mod period). If either input is an unresolved parameter, returns a == b.

Parameters:

a – A Cirq parameter value.
b – A Cirq parameter value.
period – The parameter period (i.e., cycle time).
atol – The absolute tolerance for equality checking.

Returns:

A boolean indicating whether input parameters are approximately equal.

cirq_superstaq.ops.qubit_gates.barrier(*qubits: cirq.Qid) → cirq.Operation

Equivalent to https://qiskit.org/documentation/stubs/qiskit.circuit.library.Barrier.html.

Parameters:: qubits – The qubits that the barrier will cover.
Returns:: A barrier cirq.Operation on the provided qubits.

cirq_superstaq.ops.qubit_gates.custom_resolver(cirq_type: str) → type[cirq.Gate] | None

Tells cirq.read_json how to deserialize cirq-superstaq’s custom gates.

Changes to gate names in this file should be reflected in this resolver. See quantumai.google/cirq/dev/serialization for more information about (de)serialization.

Parameters:: cirq_type – The string of the gate type for the serializer to resolve.
Returns:: The resolved cirq.Gate matching the input, or None if no match.

cirq_superstaq.ops.qubit_gates.parallel_gates_operation(*ops: cirq.Operation) → cirq.Operation

Constructs a parallel gates operation.

Given operations acting on disjoint qubits, constructs a single cirq_superstaq.ParallelGates instance and applies it such that each operation’s .gate is applied to its .qubits.

Parameters:

ops – Operations to pack into a single ParallelGates operation.

Returns:

ParallelGates(op.gate, op2.gate, …).on(*op.qubits, *op2.qubits, …)

Raises:

ValueError – If the operation has no .gate attribute.
ValueError – If the operation has tags.

cirq_superstaq.ops.qubit_gates.AQTICCX

cirq_superstaq.ops.qubit_gates.AQTITOFFOLI

cirq_superstaq.ops.qubit_gates.AceCRMinusPlus

cirq_superstaq.ops.qubit_gates.AceCRPlusMinus

cirq_superstaq.ops.qubit_gates.CR

cirq_superstaq.ops.qubit_gates.DD

cirq_superstaq.ops.qubit_gates.ICCX

cirq_superstaq.ops.qubit_gates.IX

cirq_superstaq.ops.qubit_gates.ZX