Quantum Otto Engine 2D: 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 2D ensemble of qubits, drawn as a rotatable ring, splits between a lower "ground" level and an upper "excited" level in proportion to the live population, while a linked phase-space panel traces the exact (Δ, p) path of the cycle — a trapezoid whose corners move as you retune the baths and gaps. 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.