Efficiency large deviation function of quantum heat engines

Abstract The efficiency of small thermal machines is typically a fluctuating quantity. We here study the large deviation properties two exemplary quantum heat engines, harmonic oscillator and two-level Otto motors. To this end, we analytically compute their joint characteristic functions for work based on two-projective-measurement approach. investigate work–heat correlations within respective engine cycles find, generic scale-invariant that are perfectly anticorrelated adiabatic driving. In limit, effects as well fluctuations suppressed, singular stochastic equal to macroscopic efficiency.