toqito.state_props.is_mixed

Checks if a quantum state is mixed.

Module Contents

toqito.state_props.is_mixed.is_mixed(state)

Determine if a given quantum state is mixed [@WikiMixedSt].

A mixed state by definition is a state that is not pure.

Examples

Consider the following density matrix:

[

rho = begin{pmatrix}

frac{3}{4} & 0 \ 0 & frac{1}{4}

end{pmatrix} in text{D}(mathcal{X}).

]

Calculating the rank of (rho) yields that the (rho) is a mixed state. This can be confirmed in |toqito⟩ as follows:

`python exec="1" source="above" from toqito.states import basis from toqito.state_props import is_mixed e_0, e_1 = basis(2, 0), basis(2, 1) rho = 3 / 4 * e_0 @ e_0.conj().T + 1 / 4 * e_1 @ e_1.conj().T print(is_mixed(rho)) `

Parameters:

state (numpy.ndarray) – The density matrix representing the quantum state.

Returns:

True if state is mixed and False otherwise.

Return type:

bool