Tunneling in asymmetric double well: instanton calculus
arXiv:quant-ph/0209072
Abstract
The level splitting formula of an asymmetric double well potential is calculated taking into account the multi-instanton contributions (dilute gas approximation). Results can be related with known semiclassical ones obtained with a truncated hamiltonian, and the symmetric case is easily recovered.
Old paper I found in the backups, written in 1994