What is Minimal Model of 3He Adsorbed on Graphite? -Importance of Density Fluctuations in 4/7 Registered Solid -

TL;DR

This paper presents a theoretical minimal model for 3He adsorbed on graphite at 4/7 density, emphasizing the role of density fluctuations in the emergence of quantum spin liquid behavior and magnetic properties.

Contribution

It introduces a minimal model that accounts for density fluctuations and explains experimental magnetic saturation and quantum spin liquid emergence.

Findings

Density fluctuations are crucial near the fluid-solid boundary.

Large magnetic fields are needed for saturation due to density fluctuations.

Quantum spin liquid behavior is linked to mechanisms similar to the Hubbard model.

Abstract

We show theoretically that the second layer of 3He adsorbed on graphite and solidified at 4/7 of the first-layer density is close to the fluid-solid boundary with substantial density fluctuations on the third layer. The solid shows a translational symmetry breaking as in charge-ordered insulators of electronic systems. We construct a minimal model beyond the multiple-exchange Heisenberg model. An unexpectedly large magnetic field required for the measured saturation of magnetization is well explained by the density fluctuations. The emergence of quantum spin liquid is understood from the same mechanism as in the Hubbard model and in \kappa-(ET)_2Cu_2(CN)_3 near the Mott transitions.