Quenching of macroscopic quantum coherence and macroscopic Fermi-particle configurations

Abstract

Starting from the coherent state representation of the evolution operator with the help of the path-integral, we derive a formula for the low-lying levels E = ε₀ − 2Δ εcos(s + ξ)π in disagreement with the suppression of tunneling (i.e. Δε = 0)as claimed in the literature. A new configuration called the macroscopic Fermi-particle is suggested by the nature of its wave function. The tunneling rate $\left( {\frac{{2\Delta \varepsilon }} {\pi }} \right)$ does not vanish, not for integer spin s nor for a half-integer value of s, and is calculated explicitly (for the position dependent mass) up to the one-loop approximation.