dq.parity

parity(dim: int) -> Array

Returns the parity operator of a bosonic mode.

It is defined by \(P = e^{i\pi a^\dag a}\), where \(a\) and \(a^\dag\) are the annihilation and creation operators, respectively.

Parameters

• dim –

  Dimension of the Hilbert space.

Returns

(array of shape (dim, dim)) Parity operator.

Examples

>>> dq.parity(4)
Array([[ 1.+0.j,  0.+0.j,  0.+0.j,  0.+0.j],
       [ 0.+0.j, -1.+0.j,  0.+0.j,  0.+0.j],
       [ 0.+0.j,  0.+0.j,  1.+0.j,  0.+0.j],
       [ 0.+0.j,  0.+0.j,  0.+0.j, -1.+0.j]], dtype=complex64)