Unusual temperature evolution of band structure of Bi(111) studied by angle-resolved photoemission spectroscopy and density functional theory

TL;DR

This study investigates how the band structure of Bi(111) thin films changes with temperature using ARPES and DFT, revealing significant energy shifts linked to lattice expansion, offering new insights into lattice-electronic interactions.

Contribution

It demonstrates a large temperature-dependent energy shift in Bi(111) surface and quantum-well states, highlighting the role of interlayer spacing changes in band structure evolution.

Findings

Large temperature variation of energy dispersion (up to 0.1 eV)

Interlayer spacing expansion at higher temperatures

Lattice-electronic interplay revealed through temperature dependence

Abstract

We have performed angle-resolved photoemission spectroscopy of Bi(111) thin films grown on Si(111), and investigated the evolution of band structure with temperature. We revealed an unexpectedly large temperature variation of the energy dispersion for the Rashba-split surface state and the quantum-well states, as seen in the highly momentum-dependent energy shift as large as 0.1 eV. A comparison of the band dispersion between experiment and first-principles band-structure calculations suggests that the interlayer spacing at the topmost Bi bilayer expands upon temperature increase. The present study provides a new pathway for investigating the interplay between lattice and electronic states through the temperature dependence of band structure.