CatState¶

Module: pennylane

class CatState(a, phi, p, wires)[source]

Prepares a cat state.

A cat state is the coherent superposition of two coherent states,

$\ket{\text{cat}(\alpha)} = \frac{1}{N} (\ket{\alpha} +e^{ip\pi} \ket{-\alpha}),$

where $$\ket{\pm\alpha} = D(\pm\alpha)\ket{0}$$ are coherent states with displacement parameters $$\pm\alpha=\pm ae^{i\phi}$$ and $$N = \sqrt{2 (1+\cos(p\pi)e^{-2|\alpha|^2})}$$ is the normalization factor.

Details:

• Number of wires: 1
• Number of parameters: 3
• Gradient recipe: None (uses finite difference)
Parameters: a (float) – displacement magnitude $$a=|\alpha|$$ phi (float) – displacement angle $$\phi$$ p (float) – parity, where $$p=0$$ corresponds to an even cat state, and $$p=1$$ an odd cat state. wires (Sequence[int] or int) – the wire the operation acts on