量子

• Reading: りょうし
• Romaji: ryoshi
• Kanji breakdown: 量 (ryou) — quantity, amount, measure; 子 (shi) — child, particle, small unit
• Pronunciation: /ɾʲoː.ɕi/

Meaning

Quantum. The smallest discrete unit of a physical quantity, especially electromagnetic energy, as described by quantum theory.

The concept that energy and other physical quantities come in discrete packets is foundational to modern physics. 量子力学 (quantum mechanics) describes matter and energy at atomic and subatomic scales. Compound forms include 量子コンピュータ (quantum computer), 量子暗号 (quantum cryptography), and 量子もつれ (quantum entanglement). Its implications have reshaped chemistry, materials science, and information technology.

Examples

1. 量子力学によれば、電子は粒子と波の性質を同時に持つ。 According to quantum mechanics, an electron simultaneously possesses the properties of both a particle and a wave.
2. 量子コンピュータは従来のコンピュータでは解けない問題を短時間で処理できる可能性がある。 Quantum computers have the potential to process problems that conventional computers cannot solve in a short time.
3. 量子もつれを利用した通信技術は、理論上盗聴が不可能だとされている。 Communication technology using quantum entanglement is theoretically said to be impossible to intercept.

Usage Guide

Context: physics, quantum computing, chemistry, technology

Tone: scientific

Origin & History

Introduced into Japanese physics vocabulary during the Meiji-Taisho period as a translation of the German Quant (coined by Max Planck). 量 means quantity and 子 means particle or small unit.

Cultural Context

Era: Taisho–Modern

Generation: Adults (academic/technical)

Social background: Academic/Technical