@qiskit/sim

Qiskit.js simulator

Quantum Information Science Kit simulator in pure JavaScript. As a first feature it includes an unitary one, with specific support for OpenQASM circuits representation.

Please visit the main repository to know more about the rest of the project tools.

Install

Install lastest Node.js stable version (or LTS) and then:

npm i @qiskit/sim

Use

You can visit more complete examples in the tests.

const util = require('util');

const { Circuit, Gate } = require('@qiskit/sim');

function randomizeInput(nQubits) {
  const input = [];

  for (let i = 0; i < nQubits; i += 1) {
    const x = !!Math.round(Math.random());
    input.push(x);

    console.log(`${i}:${x ? '|1>' : '|0>'}`);
  }

  return input;
}

const circuit = Circuit.createCircuit(2);

circuit.add(Gate.h, 0, 0);
circuit.add(Gate.cx, 1, [0, 1]);
circuit.print();

console.log('\nInput randomized (as string):');
const input = randomizeInput(circuit.nQubits);

console.log('\nInput randomized:');
console.log(input);

console.log('\nRunning the circuit now ...');
circuit.run(input);

console.log('\nDone, internal state:');
console.log(circuit.state);

console.log('\nInternal state (as string):');
console.log(circuit.stateToString());

const circuitIr = circuit.save();
console.log('\nSaved IR:');
console.log(util.inspect(circuitIr, { showHidden: false, depth: null }));

API

Full specification.

version

The actual version of the library.

• version (string) - Version number.

gates

Gates definition.

• gates (object) - Supported gates definition.

Circuit(opts) -> circuit

• opts (object) -The constructor accepts next options:
  • nQubits (number) - Number of qubits needed to run the circuit. It will be automatically updated by the addGate method if needed.
• circuit (object) - New instance.

circuit.state

• state (object, Math.js matrix) - Internal state of the simulation.

circuit.stateToString() -> stateStr

• stateStr (string) - Human friendly representation of the internal state.

circuit.addGate(gate, column, wires)

Add a gate to the circuit.

• gate (Gate|string) - Gate instance or name of the gate, from gates field.
• column (number) - Qubit to connect the gate.
• wires (number / [number]) - Gate connections. An array is used for multi-gates.

circuit.add(gate, column, wires)

Add a gate to the circuit. This function is identical to addGate but only accepts Gate instances.

• gate (Gate) - Gate instance to add to the circuit.
• column (number) - Qubit to connect the gate.
• wires (number / [number]) - Gate connections. An array is used for multi-gates.

circuit.print([writable])

Prints a visual representation of the circuit to standard out (by default).

• writable (object) - Optional Writable object which will be written to. Defaults to process.stdout.

circuit.run(input)

Make the simulation.

• input ([boolean]) - Initial state of each qubit.

circuit.save() -> circuitIr

Export the circuit setup for a future reuse.

• circuitIr (object) - Simulator internal representation of the circuit (JSON).

circuit.load(circuitIr)

Import a circuit setup.

• circuitIr