Integral Fluctuation Theorem for Microcanonical and Pure States

We present a derivation of the integral fluctuation theorem (IFT) for isolated quantum systems based on some natural assumptions on transition probabilities. Under these assumptions of "stiffness" and "smoothness" the IFT immediately follows for microcanonical and pure quantum states. We numerically check the IFT as well as the validity of our assumptions by analyzing two exemplary systems. We have been informed by T. Sagawa et al. that he and his co-workers found comparable numerical results and are preparing a corresponding paper, which should be available on the same day as the present text. We recommend reading their submission.