🔘 Single-Electron Tunneling Events in a Quantum Dot

A single-electron transistor works because a nanoscale island's capacitance is so small that adding just one extra electron costs a real, measurable amount of energy — the Coulomb charging energy. This simulator runs a live Monte Carlo of the orthodox theory of single-electron tunneling: individual electrons hop one at a time between the source lead, the island and the drain lead, each hop drawn from a genuine Fermi golden-rule rate that depends on the gate voltage, the source–drain bias and the temperature. Sweep the gate charge through a charge-degeneracy point and watch Coulomb blockade snap off into a sharp Coulomb-oscillation current peak — the exact effect that makes single-electron transistors the most sensitive electrometers built, used to read out solid-state qubits and to define the SI ampere from counted electrons.