Classical versus Quantum Effects in the B=0 Conducting Phase in Two Dimensions

TL;DR

This paper investigates the zero-field conducting phase in two-dimensional silicon electron systems, comparing classical and quantum effects, and finds that quantum degeneracy influences the observed resistance behavior.

Contribution

It demonstrates that the anomalous zero-field resistance behavior correlates with quantum degeneracy, highlighting the role of quantum effects in 2D electron systems.

Findings

Shubnikov-de Haas oscillations and resistance decrease occur at similar temperatures.

Zero-field anomalous behavior appears only in the degenerate quantum state.

Resistance temperature dependence is similar in zero field and at integer Landau levels.

Abstract

In the dilute two-dimensional electron system in silicon, we show that the temperature below which Shubnikov-de Haas oscillations become apparent is approximately the same as the temperature below which an exponential decrease in resistance is seen in B=0, suggesting that the anomalous behavior in zero field is observed only when the system is in a degenerate (quantum) state. The temperature dependence of the resistance is found to be qualitatively similar in B=0 and at integer Landau level filling factors.