uniqc.algorithmics.state_preparation.dicke_state module

Dicke state preparation.

Prepares the symmetric Dicke state |D(n,k)> — the equal superposition of all n-qubit basis states with exactly k excitations (ones).

uniqc.algorithmics.state_preparation.dicke_state.dicke_state(circuit, qubits=None, k=1)

Prepare the symmetric Dicke state |D(n,k)>.

The Dicke state is the equal superposition of all weight-k computational basis states on n qubits:

\[\begin{split}|D(n,k)\\rangle = \\frac{1}{\\sqrt{\\binom{n}{k}}} \\sum_{\\substack{x \\in \\{0,1\\}^n \\\\ |x|=k}} |x\\rangle\end{split}\]

The target state vector is constructed directly and prepared using rotation_prepare().

Parameters:

• circuit (Circuit) – Quantum circuit (mutated in-place).

• qubits (List[int] | None) – Qubit indices to use. None → all circuit qubits.

• k (int) – Number of excitations (0 ≤ k ≤ n).

Raises:

ValueError – k is negative or exceeds the number of qubits.

Return type:

None

Example

>>> from uniqc.circuit_builder import Circuit
>>> from uniqc.algorithmics.state_preparation import dicke_state
>>> c = Circuit()
>>> dicke_state(c, qubits=[0, 1, 2], k=1)  # ``|D(3,1)>``