Effect of Intrinsic Degrees of Freedom on the Quantum Tunneling of a Collective Variable

摘要

The effect of intrinsic degrees of freedom on tunneling through a potential barrier is discussed using a BKW-like approximation. In the present work intrinsic degrees of freedom are represented by a single harmonic oscillator. The theory leads to a formula for the effect of the coupling on the decay width of a metastable state. When the frequency omega of the intrinsic degree of freedom is large then GAMMA implies GAMMAsub(ad) where GAMMAsub(ad) is the decay width calculated with the adiabatic barrier. An inequality GAMMA<=GAMMAsub(ad) is proved for any form of the coupling hamiltonian. Corrections are discussed and are shown to be of order 1/M where M is the mass of the tunneling coordinate. An application to fission is considered. The generalization of our formula for GAMMA to the case of many intrinsic degrees of freedom is given explicitely. (Atomindex citation 14:753446)