uniqc.algorithms.core.circuits.entangled_states module

Entangled state preparation circuits: GHZ, W, and Cluster states.

All three follow the circuit fragment design (see the design notes in the project README). The canonical APIs are:

• ghz_state_circuit(n_qubits, qubits=None) -> Circuit

• w_state_circuit(n_qubits, qubits=None) -> Circuit

• cluster_state_circuit(n_qubits, qubits=None, edges=None) -> Circuit

The shorter names ghz_state, w_state and cluster_state are fragment-style aliases: pass an integer n_qubits to get a fresh fragment.

uniqc.algorithms.core.circuits.entangled_states.cluster_state(n_qubits=None, qubits=None, edges=None)

Prepare a cluster (graph) state via \(H^{\otimes n}\) + CZ on each edge.

See ghz_state() for the signature contract. edges defaults to a linear nearest-neighbour chain.

uniqc.algorithms.core.circuits.entangled_states.cluster_state_circuit(n_qubits, qubits=None, edges=None)

Fragment-style alias of cluster_state().

uniqc.algorithms.core.circuits.entangled_states.entangled_states_example()

Return a dict { 'ghz': Circuit, 'w': Circuit, 'cluster': Circuit } for tests/docs.

uniqc.algorithms.core.circuits.entangled_states.ghz_state(n_qubits=None, qubits=None)

Prepare a GHZ state \((|0\ldots0\rangle + |1\ldots1\rangle)/\sqrt 2\).

c = ghz_state(3)                         # returns Circuit
c = ghz_state(3, qubits=[1, 2, 4])       # use offset qubits

Parameters:

• n_qubits – Number of qubits. May be None if qubits is given, in which case it is inferred as max(qubits) + 1.

• qubits – Qubit indices.

Returns:

A fresh Circuit containing the preparation fragment.

uniqc.algorithms.core.circuits.entangled_states.ghz_state_circuit(n_qubits, qubits=None)

Fragment-style alias of ghz_state() (always returns a fresh Circuit).

uniqc.algorithms.core.circuits.entangled_states.w_state(n_qubits=None, qubits=None)

Prepare a W state — equal superposition of single-excitation basis states.

See ghz_state() for the signature contract.

uniqc.algorithms.core.circuits.entangled_states.w_state_circuit(n_qubits, qubits=None)

Fragment-style alias of w_state().