QCircuit¶

Defined in QCircuit.hpp.

This is a class that represents and optimizes a simple quantum “circuit,” (without directly simulating it). Its constructor argument turns on-the-fly circuit simplification on or off.

Via QCircuitGate, the fundamental “atomic” gate of a QCircuit is “uniformly controlled.” (See Quantum circuits with uniformly controlled one-qubit gates.) In other words, a different “target qubit payload” (as a 2x2 operator on a single qubit, controlled) is associated with every logical permutation of control qubits, which can greatly optimize performance through coalescence in an efficient form for state vector simulation.

inline Qrack::QCircuit::QCircuit(bool collapse = true, bool clifford = false)¶: Default constructor.

inline Qrack::QCircuit::QCircuit(bitLenInt qbCount, const std::list<QCircuitGatePtr> &g, bool collapse = true, bool clifford = false)¶: Manual constructor.

inline QCircuitPtr Qrack::QCircuit::Clone()¶

inline QCircuitPtr Qrack::QCircuit::Inverse()¶

inline void Qrack::QCircuit::Append(QCircuitPtr circuit)¶: Append circuit (with identical qubit index mappings) at the end of this circuit.

inline void Qrack::QCircuit::Combine(QCircuitPtr circuit)¶: Combine circuit (with identical qubit index mappings) at the end of this circuit, by acting all additional gates in sequence.

bool Qrack::QCircuit::AppendGate(QCircuitGatePtr nGate)¶: Add a gate to the gate sequence.

void Qrack::QCircuit::Run(QInterfacePtr qsim)¶: Run this circuit.

inline bitLenInt Qrack::QCircuit::GetQubitCount()¶: Get the (automatically calculated) count of qubits in this circuit, so far.

inline void Qrack::QCircuit::SetQubitCount(bitLenInt n)¶: Set the count of qubits in this circuit, so far.

inline std::list<QCircuitGatePtr> Qrack::QCircuit::GetGateList()¶: Return the raw list of gates.

inline void Qrack::QCircuit::SetGateList(std::list<QCircuitGatePtr> gl)¶: Set the raw list of gates.

inline void Qrack::QCircuit::Swap(bitLenInt q1, bitLenInt q2)¶: Add a Swap gate to the gate sequence.

inline bool Qrack::QCircuit::IsNonPhaseTarget(bitLenInt qubit)¶: Check if an index is any target qubit of this circuit.

inline void Qrack::QCircuit::DeletePhaseTarget(bitLenInt qubit, bool eigen)¶: (If the qubit is not a target of a non-phase gate…) Delete this qubits’ controls and phase targets.

inline QCircuitPtr Qrack::QCircuit::PastLightCone(std::set<bitLenInt> &qubits)¶: Return (as a new QCircuit) just the gates on the past light cone of a set of qubit indices.

QCircuitGate¶

inline Qrack::QCircuitGate::QCircuitGate()¶: Identity gate constructor.

inline Qrack::QCircuitGate::QCircuitGate(bitLenInt q1, bitLenInt q2)¶: Swap gate constructor

inline Qrack::QCircuitGate::QCircuitGate(bitLenInt trgt, const complex matrix[])¶: Single-qubit gate constructor.

inline Qrack::QCircuitGate::QCircuitGate(bitLenInt trgt, const complex matrix[], const std::set<bitLenInt> &ctrls, const bitCapInt &perm)¶: Controlled gate constructor.

inline Qrack::QCircuitGate::QCircuitGate(bitLenInt trgt, const std::map<bitCapInt, std::shared_ptr<complex>> &pylds, const std::set<bitLenInt> &ctrls)¶: Uniformly controlled gate constructor (that only accepts control qubits is ascending order)