VolksRat71 / quantum

An attempt at understanding qunatum computing with a classical computer using JavaScript and Python. Smart. I know.

An example of a simple quantum computing algorithm using Qiskit.js, which is a JavaScript library for quantum computing developed by IBM.

The example algorithm we will implement is called the Quantum Teleportation Algorithm. This algorithm uses quantum entanglement to transmit the quantum state of one qubit to another qubit that is physically separated from the first one.

Here is the code:

const { Circuit, Gate, Qubit } = require('qiskit');

const circuit = new Circuit();

// Create three qubits
const q0 = new Qubit();
const q1 = new Qubit();
const q2 = new Qubit();

// Entangle qubits 1 and 2
circuit.add(Gate.H(q1));
circuit.add(Gate.CX(q1, q2));

// Prepare qubit 0 in a random state
const randomState = Math.random() < 0.5 ? [1, 0] : [0, 1];
q0.applyState(randomState);

// Apply teleportation protocol
circuit.add(Gate.CX(q0, q1));
circuit.add(Gate.H(q0));
const [c0, c1] = circuit.measure([q0, q1]);
if (c1 === 1) {
  circuit.add(Gate.X(q2));
}
if (c0 === 1) {
  circuit.add(Gate.Z(q2));
}

console.log(`Initial state: ${randomState}`);
console.log(`Final state: ${q2.getState()}`);

In this code, we first create three qubits using the Qubit class. We then entangle qubits 1 and 2 using the Hadamard gate (Gate.H()) and the controlled-NOT gate (Gate.CX()).

Next, we prepare qubit 0 in a random state using the applyState() method. We then apply the teleportation protocol using controlled-NOT and Hadamard gates, and measure qubits 0 and 1 using the measure() method.

Depending on the measurement outcomes, we apply Pauli X and Z gates to qubit 2 using the Gate.X() and Gate.Z() methods. Finally, we output the initial and final states of qubit 2 using the getState() method.

Note that this code is a simplified example for demonstration purposes only, and actual quantum teleportation protocols can be more complex and involve additional steps.