Strongly enhanced effective mass in dilute two-dimensional electron systems: System-independent origin

TL;DR

This study measures the effective mass in dilute 2D electron systems in (111)-silicon, revealing a system-independent enhancement driven by electron-electron interactions, consistent across different silicon orientations.

Contribution

It demonstrates that the effective mass enhancement in dilute 2D electron systems is system-independent and primarily governed by electron-electron interactions.

Findings

Effective mass increases as electron density decreases.

Mass renormalization aligns with previous (100)-silicon results.

System independence suggests universal interaction effects.

Abstract

We measure the effective mass in a dilute two-dimensional electron system in (111)-silicon by analyzing temperature dependence of the Shubnikov-de Haas oscillations in the low-temperature limit. A strong enhancement of the effective mass with decreasing electron density is observed. The mass renormalization as a function of the interaction parameter r_s is in good agreement with that reported for (100)-silicon, which shows that the relative mass enhancement is system- and disorder-independent being determined by electron-electron interactions only.