Crate burn_quantum 

Quantum simulation and differentiable circuits on Burn 0.22.

Public tensors use Burn’s runtime Device dispatch. QuantumBackend is a quantum execution contract, not a replacement for Burn’s fixed catalog of classical tensor backends. See the repository’s architecture document for extension and scaling boundaries.

use burn::tensor::Device;
use burn_quantum::{Circuit, DenseSimulator, QuantumBackend, Register, Unitary};
let mut circuit = Circuit::new(Register::qubits(2)?, 0, 0);
circuit.unitary(vec![0], Unitary::h())?;
circuit.unitary(vec![0, 1], Unitary::cnot())?;
let state = DenseSimulator::default()
    .execute(&circuit, None, None, 1, &Device::flex())?;
state.validate(1e-5)?;

Re-exports

pub use backend::Capabilities;

pub use backend::DenseSimulator;

pub use backend::QuantumBackend;

pub use backend::ResourceLimits;

pub use circuit::Angle;

pub use circuit::Circuit;

pub use circuit::Operation;

pub use circuit::Rotation;

pub use complex::ComplexTensor;

pub use error::Error;

pub use error::Result;

pub use gate::Matrix;

pub use gate::Unitary;

pub use layout::Register;

pub use noise::DensityMatrix;

pub use noise::KrausChannel;

pub use observable::Hamiltonian;

pub use observable::Observable;

pub use quantum_module::QuantumLayer;

pub use quantum_module::QuantumLayerConfig;

pub use sampling::Samples;

pub use state::StateVector;

Modules

algorithms

Reusable canonical circuit constructions. All wires use big-endian register order. These are dense-simulation-sized templates, not claims of classical quantum speedup.

backend

Execution contract and the native Burn dense simulator.

circuit

Versioned, serializable circuit structure and differentiable parameter binding.

complex

Complex numbers represented by a pair of ordinary differentiable tensors.

error

Recoverable validation errors at the quantum API boundary.

gate

Validated constant matrices and differentiable two-level rotations.

gradient

Exact occurrence-wise parameter shifts for supported analytic rotations.

layout

Mixed-radix layouts. Wire zero is the most significant digit.

noise

Exact mixed states, partial traces, and completely positive trace-preserving channels.

observable

Local Hermitian observables and sparse sums of local terms.

optim

Evaluation-based quantum optimizers using native Burn parameter tensors.

photonic

Photonic/FBQC models with explicit physical representations and execution budgets.

protocol

Explicit measurement and classical feed-forward over an ordinary unitary circuit. A branch is selected by supplied outcomes, not sampled or silently postselected.

qml

Reusable quantum feature encoding, circuit templates, kernels, and losses.

quantum_module

Native Burn trainable quantum layer.

sampling

Explicit nondifferentiable terminal measurement with local reproducible RNG.

sat

Grover search for classical Boolean CNF satisfiability.

state

Batched pure-state simulation.

tensor_network

Bounded matrix-product-state (MPS) simulation for qubits and mixed qudits.