Quantum Double-Barrier Tunneling

Transfer matrix method · transmission resonances · resonant tunneling

Barrier Parameters

Barrier height V₀: 5.0 eV Barrier width d: 1.0 Å Well width w: 2.0 Å Energy E: 2.0 eV

Transmission T: —

Reflection R: —

Resonance: —

Green curve: T(E) sweep
Vertical line: current E
Resonance peaks: T→1

Two rectangular barriers with a quantum well between them act as a Fabry-Pérot resonator for matter waves. The transfer matrix method chains 2×2 matrices across each region. At resonant energies matching quasi-bound states in the well, transmission spikes to T = 1 — perfect transmission despite opaque barriers. This underlies resonant tunneling diodes (RTDs).