Tunneling and interaction effects in two-level systems in glasses studied by atomistic simulations

We use molecular dynamics simulations to characterize low-energy two-level systems (TLS) in glasses. We estimate that in silica glass, TLS parameters are broadly distributed in such a way that the tunnel splitting is in the 0.01–1 K range. We also observe simultaneous atomic jumps in different TLS below 30 K and suggest that this is evidence of strong interaction between TLS below this temperature scale