



01828nas a2200145   4500008004100000245015000041210006900191260001400260490000700274520129600281100002701577700002201604700001901626856003701645       2014                        eng d00aNonequilibrium quantum fluctuations of a dispersive medium: Spontaneous  emission, photon statistics, entropy generation, and stochastic motion
0 aNonequilibrium quantum fluctuations of a dispersive medium Spont  c2014/7/160 v903 a  We study the implications of quantum fluctuations of a dispersive medium,
under steady rotation, either in or out of thermal equilibrium with its
environment. A rotating object exhibits a quantum instability by dissipating
its mechanical motion via spontaneous emission of photons, as well as internal
heat generation. Universal relations are derived for the radiated energy and
angular momentum as trace formulas involving the object's scattering matrix. We
also compute the quantum noise by deriving the full statistics of the radiated
photons out of thermal and/or dynamic equilibrium. The (entanglement) entropy
generation is quantified, and the total entropy is shown to be always
increasing. Furthermore, we derive a Fokker-Planck equation governing the
stochastic angular motion resulting from the fluctuating back-reaction
frictional torque. As a result, we find a quantum limit on the uncertainty of
the object's angular velocity in steady rotation. Finally, we show in some
detail that a rotating object drags nearby objects, making them spin parallel
to its axis of rotation. A scalar toy model is introduced in the first part to
simplify the technicalities and ease the conceptual complexities; a detailed
discussion of quantum electrodynamics is presented in the second part.
1 aMaghrebi, Mohammad, F.1 aJaffe, Robert, L.1 aKardar, Mehran  uhttp://arxiv.org/abs/1401.0701v1