Chemical potential standard for atomic Bose-Einstein condensates

Abstract

When subject to an external time-periodic perturbation of frequency f, a Josephson-coupled two-state Bose-Einstein condensate may respond with a constant chemical potential difference Δμ = khf, where h is Planck's constant and k is an integer. We propose an experimental procedure to produce ac-driven atomic Josephson devices that can be used to define a standard of chemical potential. We investigate how to circumvent some of the specific problems derived from the present lack of advanced atom circuit technology. We include the effect of dissipation due to quasiparticles, which is essential to help the system relax towards the exact Shapiro resonance, and set limits to the range of values which the various physical quantities must have in order to favour the achievement of a stable and accurate chemical potential difference between the macroscopic condensates.