dq.displace
displace(dim: int, alpha: ArrayLike) -> DenseQArray
Returns the displacement operator of complex amplitude \(\alpha\).
It is defined by $$ D(\alpha) = \exp(\alpha a^\dag - \alpha^* a), $$ where \(a\) and \(a^\dag\) are the annihilation and creation operators, respectively.
Parameters
-
dim
–
Dimension of the Hilbert space.
-
alpha
(array-like of shape (...))
–
Displacement amplitude.
Returns
(qarray of shape (..., dim, dim)) Displacement operator.
Examples
>>> dq.displace(4, 0.5)
QArray: shape=(4, 4), dims=(4,), dtype=complex64, layout=dense
[[ 0.882+0.j -0.441+0.j 0.156+0.j -0.047+0.j]
[ 0.441+0.j 0.662+0.j -0.542+0.j 0.27 +0.j]
[ 0.156+0.j 0.542+0.j 0.442+0.j -0.697+0.j]
[ 0.047+0.j 0.27 +0.j 0.697+0.j 0.662+0.j]]
>>> dq.displace(4, [0.1, 0.2]).shape
(2, 4, 4)