Grand canonical Peierls transition in In/Si(111)

TL;DR

This paper models the metal-insulator transition in In/Si(111) as a grand canonical Peierls transition, explaining metastability and doping effects, supported by Raman scattering experiments showing mode softening.

Contribution

It introduces a Su-Schrieffer-Heeger-like model for In/Si(111) that captures the first-order grand canonical Peierls transition and explains experimental observations.

Findings

Metastable metallic phase exists over a wide temperature range.

Transition sensitivity to doping is explained by the model.

Raman experiments show softening of Peierls modes near transition.

Abstract

Starting from a Su-Schrieffer-Heeger-like model inferred from first-principles simulations, we show that the metal-insulator transition in In/Si(111) is a first-order grand canonical Peierls transition in which the substrate acts as an electron reservoir for the wires. This model explains naturally the existence of a metastable metallic phase over a wide temperature range below the critical temperature and the sensitivity of the transition to doping. Raman scattering experiments corroborate the softening of the two Peierls deformation modes close to the transition.