Melting of a 2D Quantum Electron Solid in High Magnetic Field

TL;DR

This paper provides experimental evidence that the melting temperature of a 2D electron solid in high magnetic fields is governed by quantum correlations, specifically the Landau level filling factor, rather than density or pressure.

Contribution

It demonstrates that the melting behavior of a 2D quantum electron solid is controlled by quantum correlations, revealing a unique quantum-driven melting mechanism distinct from classical solids.

Findings

Melting temperature depends on Landau level filling factor $ u$.

Melting temperature increases with disorder strength.

Quantum correlations govern the melting of the 2D electron solid.

Abstract

The melting temperature ($T_m$) of a solid is generally determined by the pressure applied to it, or indirectly by its density ($n$) through the equation of state. This remains true even for helium solids\cite{wilk:67}, where quantum effects often lead to unusual properties\cite{ekim:04}. In this letter we present experimental evidence to show that for a two dimensional (2D) solid formed by electrons in a semiconductor sample under a strong perpendicular magnetic field\cite{shay:97} ($B$), the $T_m$ is not controlled by $n$, but effectively by the \textit{quantum correlation} between the electrons through the Landau level filling factor $\nu$=$nh/eB$. Such melting behavior, different from that of all other known solids (including a classical 2D electron solid at zero magnetic field\cite{grim:79}), attests to the quantum nature of the magnetic field induced electron solid. Moreover, we found the $T_m$ to increase with the strength of the sample-dependent disorder that pins the electron solid.