quantum computing

for JavaScripters

Jesús Pérez

Backend Dev

@jesusprubio

quantum mechanics

qubit

superposition

entaglement

the states of entangled qubits cannot be described independently of each other

algorithms

new kind of computing

wave–particle duality

gates

single-qubit

superposition

reversible

entaglement

history

Early 80's

Theories pointing to the possibility the first calculations of a quantum nature began to emerge.

90's

Theory becomes practice: first experiments, quantum algorithms/applications and the first machines capable of performing quantum calculations.

> 2000

First chips, qubit quality.

quality

5 Quantum Computing Misconceptions: https://www.youtube.com/watch?v=kEry1TaN4-k

decoherence

In the 1990s a good qubit might last one nanosecond (a thousandth of a millionth of a second). Today, a high-quality qubit lasts 50-100 ms. The lifespan is still short, but long enough to perform calculations

Darío Gil, IBM, TechCrunch 2018

John Preskill, https://quantum-journal.org/papers/q-2018-08-06-79/pdf

Quantum technologists should continue to strive for more accurate quantum gates and, eventually, fully fault-tolerant quantum computing.

We may feel confident that quantum technology will have a substantial impact on society in the decades ahead, but we cannot be nearly so confident about the commercial potential of quantum technology in the near term, say the next five to ten years.

quantum advantage

use cases

300 Qubits

particles of the Universe

chemistry sim

Nº electrons	Hadware
25	Laptop
43	GPU
50	Supercomputers

Molecule	Experimental	Calculated	Error
CaF Fluoruro de calcio	1.967	4.079	2.112
Na2 Sodio	3.079	2.379	-0.7

other

encryption

cryptanalysis

28,000,000,000,000,000,000,000 years vs 100 seconds

rsa vs shor

ecc

Even then, certain problem will require more than the noisy qubits we work with today. The holy grail is to build a fault tolerant universal quantum computer. One concern about quantum computers is the potential to break today’s factor-based cryptography. To do so reliably will require these fault tolerant systems, which are years, probably decades away

Darío Gil, IBM, TechCrunch 2018

hardware

circuit

openqasm

openpulse

tools

quantum experience

soon

algorithms

Grover’s algorithm
Deutsch-Jozsa algorithm
Learning parity with noise
Phase estimation algorithm
Shor’s Algorithm

https://math.nist.gov/quantum/zoo

'use strict';

const qiskit = require('@qiski/devs');


qiskit.random().then(rand => console.log(`Random number(default): ${rand}`));


qiskit
  .random({
    engine: 'anu',
    // engine: 'ibm',
    // backend: 'ibmqx3',
  })
  .then(rand => console.log(`Random number: ${rand}`));


qiskit.factor(15).then(factor => console.log(`Factor: ${factor}`));

Qiskit.js

true random number

'use strict';

const utils = require('./utils');
const { version } = require('../package');

const dbg = utils.debug(__filename);

module.exports = (neededQubits = 4) => {
  let circuit =
    `// Cirtuit generated by Qiskit.js, version: ${version}\n\n` +
    'include "qelib1.inc";\n\n' +
    `qreg q[${neededQubits}];\n` +
    `creg c[${neededQubits}];\n\n`;

  let i = 0;
  utils.times(neededQubits, () => {
    circuit += `h q[${i}];\n`;
    i += 1;
  });

  circuit += '\n';

  i = 0;
  utils.times(neededQubits, () => {
    circuit += `measure q[${i}] -> c[${i}];\n`;
    i += 1;
  });

  dbg('Built circuit:', { circuit });
  return circuit;
};