cqlib-core

cqlib-core is the Rust implementation at the heart of the Cqlib quantum computing SDK. It provides circuit construction, symbolic parameters, compilation and optimization, device modeling, simulation, error mitigation, intermediate-representation support, and visualization.

Beta release: cqlib-core is under active development. Public APIs may change before the first stable release.

Installation

Add the crate to your project:

[dependencies]
cqlib-core = "0.1.0-beta.6"

Or use Cargo:

cargo add cqlib-core@0.1.0-beta.6

Quick start

Create a Bell-state circuit:

use cqlib_core::circuit::{Circuit, Qubit};

let mut circuit = Circuit::new(2);
circuit.h(Qubit::new(0))?;
circuit.cx(Qubit::new(0), Qubit::new(1))?;

assert_eq!(circuit.num_qubits(), 2);
assert_eq!(circuit.operations().len(), 2);

# Ok::<(), cqlib_core::circuit::CircuitError>(())

Create and bind a parameterized circuit:

use cqlib_core::circuit::{Circuit, Parameter, Qubit};
use std::collections::HashMap;

let theta = Parameter::symbol("theta");

let mut circuit = Circuit::new(2);
circuit.rx(Qubit::new(0), theta.clone())?;
circuit.ry(Qubit::new(1), theta)?;
circuit.cx(Qubit::new(0), Qubit::new(1))?;

let mut bindings = HashMap::new();
bindings.insert("theta", 0.5);
let bound = circuit.assign_parameters(&Some(bindings))?;

assert!(bound.parameters().is_empty());

# Ok::<(), cqlib_core::circuit::CircuitError>(())

Capabilities

• Circuit construction — Static, parameterized, and dynamic circuits with measurement-driven classical control flow
• Gate library — Standard, controlled, multi-controlled, composite, and custom unitary gates
• Symbolic parameters — Expression parsing, arithmetic, simplification, differentiation, and parameter binding
• Compilation — Decomposition, optimization, layout, routing, scheduling, and rule-based rewriting
• Device modeling — Qubit topology, layouts, calibration properties, and noise models
• Simulation — Statevector, density-matrix, noisy density-matrix, and stabilizer simulation
• Quantum information — Pauli operators, Hamiltonians, observables, evolution, fermionic algebra, excitation generators, Jordan–Wigner mapping, metrics, and entropy functions
• Error mitigation — Zero-noise extrapolation and virtual distillation
• Interchange formats — OpenQASM 2, OpenQASM 3, and QCIS
• Visualization — Text and SVG circuit rendering plus state and result plots

Main modules

Documentation and support

• Rust API documentation
• Cqlib documentation
• Source repository
• Issue tracker

Development

From the repository root:

cargo check -p cqlib-core --locked
cargo test -p cqlib-core --locked
cargo doc -p cqlib-core --no-deps

Before publishing:

cargo publish --dry-run --registry crates-io -p cqlib-core --locked

License

Cqlib is distributed under the Apache License 2.0.