Squeezing¶

Module: pennylane

class Squeezing(r, phi, wires)[source]

Phase space squeezing.

$S(z) = \exp\left(\frac{1}{2}(z^* \a^2 -z {\a^\dagger}^2)\right).$

where $$z = r e^{i\phi}$$.

Details:

• Number of wires: 1

• Number of parameters: 2

• Gradient recipe: $$\frac{d}{dr}f(S(r,\phi)) = \frac{1}{2\sinh s} \left[f(S(r+s, \phi)) - f(S(r-s, \phi))\right]$$, where $$s$$ is an arbitrary real number ($$0.1$$ by default) and $$f$$ is an expectation value depending on $$S(r,\phi)$$.

• Heisenberg representation:

$\begin{split}M = \begin{bmatrix} 1 & 0 & 0 \\ 0 & \cosh r - \cos\phi \sinh r & -\sin\phi\sinh r \\ 0 & -\sin\phi\sinh r & \cosh r+\cos\phi\sinh r \end{bmatrix}\end{split}$
Parameters: r (float) – squeezing amount phi (float) – squeezing phase angle $$\phi$$ wires (Sequence[int] or int) – the wire the operation acts on