Quantum Otto Engine: A Qubit Heat Engine

This simulator drives a single two-level quantum system — a qubit — around a full quantum Otto cycle. During the two isochoric strokes the qubit's energy gap is held fixed while it thermalizes toward the Gibbs population of whichever bath it is coupled to; during the two adiabatic strokes the gap itself is swept while the quantum adiabatic theorem keeps the population frozen, converting the change in mean energy into mechanical work. A 3D ensemble of qubits (rendered as spheres) splits between a lower "ground" plate and an upper "excited" plate in proportion to the live population, while the plate separation animates the instantaneous gap Δ(t). Tune the hot and cold bath temperatures and the gap extremes to see how the accumulated heat Qh, Qc, the net work per cycle, and the resulting efficiency compare against the theoretical bound η ≤ 1 − Δc/Δh.