dq.vacuum

vacuum(dim: int) -> QArray

Returns the ket of the vacuum state.

It is the Fock state with zero photon, defined by \(\ket{0} = \begin{pmatrix}1\\0\\\vdots\end{pmatrix}\).

Parameters:

• dim –

  Hilbert space dimension of the mode.

Returns:

• (qarray of shape (dim, 1)) –

  Ket \(\ket{0}\).

Examples:

>>> dq.vacuum(4)
QArray: shape=(4, 1), dims=(4,), dtype=complex64, layout=dense
[[1.+0.j]
 [0.+0.j]
 [0.+0.j]
 [0.+0.j]]