Search for tunnelling centres in Lennard-Jones clusters

TL;DR

This paper explores numerical methods to identify tunnelling centers in Lennard-Jones clusters, which serve as simple models for glasses, focusing on double-well potentials and quantum tunnelling effects.

Contribution

It introduces numerical procedures for detecting tunnelling centers and discusses the application of semiclassical WKB approximation in multidimensional systems.

Findings

Identification of candidate double-well potentials for two-level systems

Analysis of boundary effects on tunnelling calculations

Application of WKB approximation to ground state splitting

Abstract

We report on numerical procedures for, and preliminary results on the search for, tunnelling centres in Lennard-Jones clusters, seen as simple model systems of glasses. Several of the double-well potentials identified are good candidates to give rise to two-level systems. The role of boundary effects, and the application of the semiclassical WKB approximation in multidimensional spaces for the calculation of the ground state splitting are discussed.