# Quantum Computing Explained

> Quantum computers exploit the peculiar physics of subatomic particles to solve certain problems exponentially faster than classical machines.

*Section: Technology — By Amelia Hart (Technology Correspondent) — Published September 15, 2025 — 1 min read*

Canonical URL: https://dailyjunction.org/technology/quantum-computing-explained
Tags: quantum computing, physics, cryptography, ibm, computing

## Key takeaways

- Quantum computers use qubits that can exist in superposition
- They excel at specific problem types: optimisation, simulation, cryptography
- Current machines are noisy and error-prone
- Quantum computers complement rather than replace classical computers

## The basic idea

Classical computers process information as bits — values of either 0 or 1. Quantum computers use qubits, which can exist in a superposition of 0 and 1 simultaneously. This, combined with quantum entanglement and interference, allows certain calculations to be performed in a fundamentally different and potentially far faster way.

## What quantum computers are good at

The advantage is not universal. Quantum computers excel at specific problem types: optimisation problems such as finding the best route through thousands of possibilities; simulation of molecular interactions for drug discovery; and cryptography — Shor's algorithm can factor large numbers exponentially faster than known classical algorithms, threatening current encryption. For running a spreadsheet or browsing the web, a quantum computer offers no advantage.

## Where we are now

Current quantum computers are NISQ machines — Noisy Intermediate-Scale Quantum. They have enough qubits to do interesting things in controlled settings, but errors accumulate quickly and fault-tolerant quantum computation at scale remains years away. IBM, Google and a growing number of startups are racing to increase qubit count while reducing error rates.

## Frequently asked questions

### Who should read this?

Anyone wanting to understand how this technology works, whether for professional development or general curiosity.

### How quickly is this area changing?

Rapidly. The fundamentals are durable, but specific tools evolve quickly. We update our technology coverage regularly.

## Sources

- [MIT Technology Review](https://www.technologyreview.com)
- [IEEE Spectrum](https://spectrum.ieee.org)
- [Wired UK](https://www.wired.co.uk)

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Daily Junction — https://dailyjunction.org/technology/quantum-computing-explained