title: Measuring nonequilibrium temperature of forced oscillators.
abstract: The meaning of temperature in nonequilibrium thermodynamics is considered by using a forced harmonic oscillator in a heat bath, where we have two effective temperatures for the position and the momentum, respectively. We propose a concrete model of a thermometer to testify the validity of these different temperatures from the operational point of view. It is found that the measured temperature depends on a specific form of interaction between the system and a thermometer, which means that the zeroth law of thermodynamics cannot be immediately extended to nonequilibrium cases.
authors.affiliation: Center for Promotion of Computational Science and Engineering, Japan Atomic Energy Research Institute, Ibaraki 319-1195, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hatano
authors.forename: David
authors.initials: D
authors.lastname: Jou