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sf.ops.MeasureHeterodyne

class MeasureHeterodyne(select=None)[source]

Bases: strawberryfields.ops.Measurement

Performs a heterodyne measurement on a mode.

Also accessible via the shortcut variable MeasureHD.

Samples the joint Husimi distribution \(Q(\vec{\alpha}) = \frac{1}{\pi}\bra{\vec{\alpha}}\rho\ket{\vec{\alpha}}\). The measured mode is reset to the vacuum state.

Warning

The heterodyne measurement can only be performed in the Gaussian or Bosonic backends.

Parameters

select (None, complex) – (Optional) desired values of measurement result. Allows the post-selection of specific measurement results instead of randomly sampling.

Definition

Heterodyne measurement is a Gaussian projective measurement given by projecting the state onto the coherent states,

\[\frac{1}{\pi} \ket{\alpha}\bra{\alpha}\]

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

Like Operation.apply(), but also stores the measurement result in the RegRefs.

Keyword Arguments

shots (int) – Number of independent evaluations to perform. Only applies to Measurements.

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

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