Ground State Energy Fluctuations of a System Coupled to a Bath
arXiv:cond-mat/0108243 · doi:10.1209/epl/i2002-00420-8
Abstract
It is often argued that a small non-degenerate quantum system coupled to a bath has a fixed energy in its ground state since a fluctuation in energy would require an energy supply from the bath. We consider a simple model of a harmonic oscillator (the system) coupled to a linear string and determine the mean squared energy fluctuations. We also analyze the two time correlator of the energy and discuss its behavior for a finite string.
5 pages, 2 eps figures, minor changes