Struct SparseBackend 

pub struct SparseBackend { /* private fields */ }

Sparse state-vector backend, O(k) where k is the number of non-zero amplitudes.

Implementations

impl SparseBackend

pub fn new(seed: u64) -> Self

Create a new sparse backend with the given RNG seed.

Trait Implementations

impl Backend for SparseBackend

fn name(&self) -> &'static str

Human-readable backend name (for error messages, logging, and benchmarks).

fn init(&mut self, num_qubits: usize, num_classical_bits: usize) -> Result<()>

Initialize (or reset) state for a circuit with the given dimensions.

fn apply(&mut self, instruction: &Instruction) -> Result<()>

Apply a single instruction to the current state.

fn reset(&mut self, qubit: usize) -> Result<()>

Reset a qubit to |0⟩, discarding any prior amplitude on that qubit.

fn reduced_density_matrix_1q(&self, qubit: usize) -> Result<[[Complex64; 2]; 2]>

Compute the one-qubit reduced density matrix without collapsing the state.

fn classical_results(&self) -> &[bool]

Read classical measurement results.

fn probabilities(&self) -> Result<Vec<f64>>

Compute the probability of each computational basis state.

fn num_qubits(&self) -> usize

Number of qubits the backend is currently configured for.

fn export_statevector(&self) -> Result<Vec<Complex64>>

Export the current quantum state as a dense statevector.

fn apply_instructions(&mut self, instructions: &[Instruction]) -> Result<()>

Apply a batch of instructions to the current state.

fn supports_fused_gates(&self) -> bool

Whether this backend can handle Gate::Fused variants.

fn supports_qft_block(&self) -> bool

Whether this backend has a native kernel for Gate::QftBlock.

fn qubit_probability(&self, qubit: usize) -> Result<f64>

Compute P(qubit = |1⟩) without collapsing the state.

fn apply_1q_matrix( &mut self, qubit: usize, matrix: &[[Complex64; 2]; 2], ) -> Result<()>

Apply a 2×2 matrix to a single qubit without allocating.