New instantons in the double-well potential

TL;DR

This paper introduces a novel instanton solution in a quantum double-well potential with fermionic interactions, highlighting how instanton actions can depend on collective coordinates.

Contribution

It presents a new instanton solution with finite action in a double-well potential including four-fermion terms, expanding understanding of instanton configurations.

Findings

New instanton solution with finite action

Dependence of instanton action on collective coordinates

Insight into fermionic effects in quantum tunneling

Abstract

A new instanton solution is found in the quantum-mechanical double-well potential with a four-fermion term. The solution has finite action and depends on four fermionic collective coordinates. We explain why in general the instanton action can depend on collective coordinates.