Quantum Dot — Coulomb Blockade

Single-electron transistor · charging energy · stability diagram

Charging Energy E_C (meV) 2.00 meV

Temperature kT (meV) 0.15 meV

Level spacing Δ (meV) 0.50 meV

Source-Drain V_SD (mV) 0.50 mV

Coulomb blockade: tunneling of single electrons onto a quantum dot is suppressed when the charging energy E_C = e²/2C exceeds thermal fluctuations. Conductance peaks appear at gate voltages where adjacent charge states are degenerate (N↔N+1 electrons). The stability diagram (left) shows differential conductance as a function of gate voltage V_G and bias V_SD, revealing diamond-shaped Coulomb blockade regions.