sf.utils.coherent_state¶
-
coherent_state
(r, phi, basis='fock', fock_dim=5, hbar=2.0)[source]¶ Returns the coherent state
This can be returned either in the Fock basis,
\[|\alpha\rangle = e^{-|\alpha|^2/2} \sum_{n=0}^\infty \frac{\alpha^n}{\sqrt{n!}}|n\rangle\]or as a Gaussian:
\[\mu = (\text{Re}(\alpha),\text{Im}(\alpha)),~~~\sigma = I\]where \(\alpha\) is the displacement.
- Parameters
r (float) – displacement magnitude
phi (float) – displacement phase
basis (str) – If ‘fock’, calculates the initial state in the Fock basis. If ‘gaussian’, returns the vector of means and the covariance matrix.
fock_dim (int) – the size of the truncated Fock basis if using the Fock basis representation
hbar (float) – (default 2) the value of \(\hbar\) in the commutation relation \([\x,\p]=i\hbar\)
- Returns
the coherent state
- Return type
array
code/api/strawberryfields.utils.coherent_state
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