dq.random.dm

dm(key: PRNGKeyArray, shape: tuple[int, ...]) -> QArray

Returns a random density matrix (hermitian, positive semi-definite, and unit trace).

Parameters:

• key –

  A PRNG key used as the random key.

• shape (shape of the form (..., n, n)) –

  Shape of the returned qarray.

Returns:

• (qarray of shape (*shape)) –

  Random density matrix.

Examples:

>>> key = jax.random.PRNGKey(42)
>>> dq.random.dm(key, (2, 2))
QArray: shape=(2, 2), dims=(2,), dtype=complex64, layout=dense
[[ 0.198+0.j    -0.044-0.392j]
 [-0.044+0.392j  0.802+0.j   ]]