Control of intervalley scattering in Bi2Te3 via temperature-dependent band renormalization

TL;DR

This study shows how temperature affects electron behavior in Bi2Te3, a topological insulator, by changing how electrons scatter, which is important for quantum technologies.

Contribution

The study reveals that temperature-induced band renormalization modulates intervalley scattering in Bi2Te3, offering a new way to control electron dynamics.

Findings

A ~15 meV band renormalization in Bi2Te3 significantly impacts bulk and surface electron scattering.

Temperature changes modulate intervalley electron-phonon scattering rates, affecting out-of-equilibrium electron dynamics.

Temperature acts as a control parameter for engineering scattering pathways in topological insulators.

Abstract

The control of out-of-equilibrium electron dynamics in topological insulators is essential to unlock their potential in next-generation quantum technologies. However, the role of temperature on the renormalization of the electronic band structure and, consequently, on out-of-equilibrium electron scattering processes is still elusive. Here, using high-resolution time- and angle-resolved photoemission spectroscopy (TR-ARPES), we show that even a modest (~15 meV) renormalization of the conduction band of Bi2Te3 can critically affect bulk and surface electron scattering processes. Supported by kinetic Monte Carlo simulations, we show that temperature-induced changes in the bulk band structure modulate the intervalley electron-phonon scattering rate, reshaping the out-of-equilibrium response and the long-lasting charge accumulation at the bottom of the conduction band. This work establishes temperature as an effective control knob for engineering scattering pathways in topological insulators.

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