dq.ground

ground() -> QArray

Returns the eigenvector with eigenvalue $-1$ of the Pauli $\sigma_z$ operator.

It is defined by $\ket{g} = \begin{pmatrix}0\\1\end{pmatrix}$.

Note

This function is named ground because $\ket{g}$ is the lower energy state of a two-level system with Hamiltonian $H=\omega \sigma_z$.

Returns

(qarray of shape (2, 1)) Ket $\ket{g}$.

Examples

>>> dq.ground()
QArray: shape=(2, 1), dims=(2,), dtype=complex64, layout=dense
[[0.+0.j]
 [1.+0.j]]