---
title: Quantum Computing
description: Page on Vedang Vatsa's site: https://veda.ng/glossary/quantum-computing
canonical: https://veda.ng/glossary/quantum-computing
last_updated: 2026-10-03
type: text/markdown
---
# Quantum Computing

Source: https://veda.ng/glossary/quantum-computing
Author: Vedang Vatsa (https://veda.ng/about)

Quantum computing uses qubits and entanglement to run algorithms that do not map cleanly onto ordinary bits.

Instead of bits that are either 0 or 1, quantum computers use qubits that can exist in a superposition of both states simultaneously. Multiple qubits can be entangled, creating correlations that let the system try many possible solutions at once. The hardware typically runs on superconducting circuits, trapped ions, or photons, kept at temperatures near absolute zero to maintain quantum coherence.

Quantum computers are not faster at everything. They excel at specific problem types, like simulating molecular interactions for drug discovery, optimizing complex logistics, and breaking certain encryption schemes. Shor's algorithm can theoretically factor large numbers exponentially faster than classical methods, which is why the cryptography community is already developing post-quantum standards.

Current quantum machines are noisy and error-prone. Practical quantum advantage for real-world problems requires error correction, which demands far more physical qubits than we have today. But progress is accelerating, and the technology poses both enormous opportunity and serious security implications. IBM and Google publish machine stats in qubits and error rates. Shor's algorithm is why NIST is standardizing post-quantum crypto now.

Glossary index: https://veda.ng/glossary