sf.ops.MSgate

class MSgate(r, phi=0.0, r_anc=10.0, eta_anc=1.0, avg=True)[source]

Bases: strawberryfields.ops.Channel

Phase space measurement-based squeezing gate.

This mode can either be implemented as the average transformation, corresponding to a Gaussian CPTP map, or as a single-shot instance of the measurement-based squeezing circuit.

Measurement-based squeezing consists of adding an ancillary squeezed mode, entangling it with the target mode at a beamsplitter, performing a homodyne measurement on the ancillary mode, and then applying a feedforward displacement to the target mode.

Parameters
  • r (float) – target squeezing magnitude

  • phi (float) – target squeezing phase

  • r_anc (float) – squeezing magnitude of the ancillary mode

  • eta_anc (float) – detection efficiency of the ancillary mode

  • avg (bool) – whether to apply the average or single-shot map

measurement_deps

Extra dependencies due to parameters that depend on measurements.

ns

measurement_deps

Extra dependencies due to parameters that depend on measurements.

Returns

dependencies

Return type

set[RegRef]

ns = 1

apply(reg, backend, **kwargs)

Ask a local backend to execute the operation on the current register state right away.

decompose(reg, **kwargs)

Decompose the operation into elementary operations supported by the backend API.

merge(other)

Merge the operation with another (acting on the exact same set of subsystems).

apply(reg, backend, **kwargs)

Ask a local backend to execute the operation on the current register state right away.

Takes care of parameter evaluations and any pending formal transformations (like dagger) and then calls Operation._apply().

Parameters
  • reg (Sequence[RegRef]) – subsystem(s) the operation is acting on

  • backend (BaseBackend) – backend to execute the operation

Returns

the result of self._apply

Return type

Any

decompose(reg, **kwargs)

Decompose the operation into elementary operations supported by the backend API.

See strawberryfields.backends.base.

Parameters

reg (Sequence[RegRef]) – subsystems the operation is acting on

Returns

decomposition as a list of operations acting on specific subsystems

Return type

list[Command]

merge(other)

Merge the operation with another (acting on the exact same set of subsystems).

Note

For subclass overrides: merge may return a newly created object, or self, or other, but it must never modify self or other because the same Operation objects may be also used elsewhere.

Parameters

other (Operation) – operation to merge this one with

Returns

other * self. The return value None represents the identity gate (doing nothing).

Return type

Operation, None

Raises

MergeFailure – if the two operations cannot be merged