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QuantBackend

axon::quant

Trait QuantBackend 

Source 
pub trait QuantBackend {
    // Required methods
    fn capacity(&self) -> usize;
    fn encode(
        &self,
        x: &[f64],
        scheme: EncodingScheme,
    ) -> Result<StateVector, QuantError>;
    fn evolve(
        &self,
        state: StateVector,
        circuit: &VariationalCircuit,
    ) -> Result<StateVector, QuantError>;
    fn measure(
        &self,
        state: &StateVector,
        observable: &PauliSum,
    ) -> Result<f64, QuantError>;
    fn kernel(
        &self,
        a: &StateVector,
        b: &StateVector,
    ) -> Result<f64, QuantError>;
}
Expand description

v2.4.0 — the algebraic-backend port (D1). The OSS crate ships the ReferenceSimulator; the enterprise QuIDD / VRAM / QPU engine implements the same trait (v2.4.0–i). A quant block’s pipeline is encode → evolve → {measure | kernel}.

Required Methods§

Source

fn capacity(&self) -> usize

Maximum register width (qubits) this backend can realise.

Source

fn encode( &self, x: &[f64], scheme: EncodingScheme, ) -> Result<StateVector, QuantError>

Project a classical real vector into a Hilbert-space state (section 3.1).

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fn evolve( &self, state: StateVector, circuit: &VariationalCircuit, ) -> Result<StateVector, QuantError>

Evolve a state under a parametric circuit U(θ) (section 3.2).

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fn measure( &self, state: &StateVector, observable: &PauliSum, ) -> Result<f64, QuantError>

Expectation E(θ) = ⟨ψ| M |ψ⟩ of a Pauli-sum observable (real, since M is Hermitian).

Source

fn kernel(&self, a: &StateVector, b: &StateVector) -> Result<f64, QuantError>

Quantum-kernel overlap K = |⟨ψ_a|ψ_b⟩|² (section 3.4, fidelity kernel).

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§