Equations · equation
Drude Conductivity
Condensed Matter · 1900
- Equation
- σ = n·e²·τ / mₑ
- Field
- Condensed Matter
- Named After
- Paul Drude
- Symbols
- σ electrical conductivity · n density of free electrons · e electron charge · τ average time between collisions · mₑ electron mass
- Year
- 1900
Significance
Metals as a pinball sea of electrons, drifting between collisions — proposed three years after the electron's discovery. Crude but unreasonably effective: it still gives the right form for conductivity, and its failures pointed straight at the quantum theory of solids.
Referenced by
constant
element
equation
theory
Open on the Equations shelf — the interactive card, the filters, and everything alongside it.