sf.ops.Pgate¶
-
class
Pgate(s)[source]¶ Bases:
strawberryfields.ops.GateQuadratic phase gate.
\[P(s) = e^{i \frac{s}{2} \hat{x}^2/\hbar}\]- Parameters
s (float) – parameter
Details and Conventions
Definition
\[P(s) = \exp\left(i \frac{s}{2 \hbar} \x^2\right), \quad P^\dagger(s) \a P(s) = \a +i\frac{s}{2}(\a +\ad)\]It shears the phase space, preserving position:
\[\begin{split}P^\dagger(s) \x P(s) &= \x,\\ P^\dagger(s) \p P(s) &= \p +s\x.\end{split}\]This gate can be decomposed as
\[P(s) = R(\theta) S(r e^{i \phi})\]where \(\cosh(r) = \sqrt{1+(\frac{s}{2})^2}, \quad \tan(\theta) = \frac{s}{2}, \quad \phi = -\sign(s)\frac{\pi}{2} -\theta\).
Attributes
Returns a copy of the gate with the self.dagger flag flipped.
Extra dependencies due to parameters that depend on measurements.
-
H¶ Returns a copy of the gate with the self.dagger flag flipped.
H stands for hermitian conjugate.
- Returns
formal inverse of this gate
- Return type
Gate
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measurement_deps¶ Extra dependencies due to parameters that depend on measurements.
- Returns
dependencies
- Return type
set[RegRef]
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ns= 1¶
Methods
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 takes into account the special nature of p[0] and applies self.dagger.- Returns
Gates do not return anything, return value is None
- Return type
None
-
decompose(reg, **kwargs)¶ Decompose the operation into elementary operations supported by the backend API.
Like
Operation.decompose(), but applies self.dagger.
-
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