@spec depth(t()) :: non_neg_integer()

Gets the depth (number of instruction layers) of the circuit.

Examples

iex> qc = Qx.create_circuit(2) |> Qx.h(0) |> Qx.x(1)
iex> Qx.QuantumCircuit.depth(qc)
2

@spec get_instructions(t()) :: [instruction()]

Gets the list of instructions in the circuit.

Examples

iex> qc = Qx.create_circuit(2) |> Qx.h(0)
iex> [{gate_name, qubits, _params}] = Qx.QuantumCircuit.get_instructions(qc)
iex> {gate_name, qubits}
{:h, [0]}

@spec get_measurements(t()) :: [measurement()]

Gets the list of measurements in the circuit.

Examples

iex> qc = Qx.create_circuit(2, 2) |> Qx.measure(0, 0)
iex> [{qubit, classical_bit}] = Qx.QuantumCircuit.get_measurements(qc)
iex> {qubit, classical_bit}
{0, 0}

@spec get_state(t()) :: Nx.Tensor.t()

Gets the initial quantum state of the circuit.

Examples

iex> qc = Qx.QuantumCircuit.new(1, 0)
iex> state = Qx.QuantumCircuit.get_state(qc)
iex> Nx.shape(state)
{2}

@spec initial_state(t()) :: Nx.Tensor.t()

Returns the circuit's initial state vector — the |0…0⟩ recipe start, not the result of running the circuit.

A Qx.QuantumCircuit is a recipe: gates are recorded, then applied when you run it. This returns the stored starting state (circuit.state). To get the state after the gates, run the circuit: Qx.get_state/1 (1-qubit) or Qx.run/2 + Qx.SimulationResult. See also reset/1 and depth/1.

Returns

The initial state vector as an Nx.Tensor of shape {2^n}.

Examples

iex> qc = Qx.QuantumCircuit.new(1, 0)
iex> state = Qx.QuantumCircuit.initial_state(qc)
iex> Nx.shape(state)
{2}

@spec measured?(t(), non_neg_integer()) :: boolean()

Checks if a qubit has been measured.

Examples

iex> qc = Qx.create_circuit(2, 2) |> Qx.measure(0, 0)
iex> Qx.QuantumCircuit.measured?(qc, 0)
true
iex> Qx.QuantumCircuit.measured?(qc, 1)
false

@spec new(pos_integer()) :: t()

Creates a new quantum circuit with only qubits (no classical bits).

Parameters

• num_qubits - Number of qubits in the circuit

Examples

iex> qc = Qx.QuantumCircuit.new(3)
iex> qc.num_qubits
3
iex> qc.num_classical_bits
0

@spec new(pos_integer(), non_neg_integer()) :: t()

Creates a new quantum circuit with specified number of qubits and classical bits.

All qubits are initialized in the |0⟩ state, and all classical bits are initialized to 0.

Parameters

• num_qubits - Number of qubits in the circuit
• num_classical_bits - Number of classical bits for measurement storage

Examples

iex> qc = Qx.QuantumCircuit.new(2, 2)
iex> qc.num_qubits
2
iex> qc.num_classical_bits
2

@spec reset(t()) :: t()

Resets the circuit to its initial state, clearing all instructions and measurements.

Note: this clears the entire circuit (instructions + measurements + state), not a single qubit. A future mid-circuit qubit reset (ROADMAP v0.9) will add a distinct operation; this function may be renamed to clear/1 at that point to disambiguate.

Examples

iex> qc = Qx.create_circuit(2, 2) |> Qx.h(0) |> Qx.measure(0, 0)
iex> qc_reset = Qx.QuantumCircuit.reset(qc)
iex> length(qc_reset.instructions)
0
iex> length(qc_reset.measurements)
0

@spec set_state(t(), Nx.Tensor.t()) :: t()

Sets the quantum state of the circuit.

The state must be a valid quantum state vector with dimension 2^n where n is the number of qubits.

Parameters

• circuit - The quantum circuit
• state - New quantum state vector

Examples

iex> qc = Qx.QuantumCircuit.new(1, 0)
iex> new_state = Nx.tensor([Complex.new(0.0, 0.0), Complex.new(1.0, 0.0)], type: :c64)
iex> qc = Qx.QuantumCircuit.set_state(qc, new_state)
iex> Nx.shape(qc.state)
{2}