Identifying diverging-effective mass in MOSFET and $^3$He systems

TL;DR

This study measures the diverging effective mass near Mott insulators in $^3$He and MOSFET systems, fitting results with an extended Brinkman-Rice model to clarify the diverging mechanism relevant for emerging devices.

Contribution

It introduces an extended Brinkman-Rice model to accurately describe the diverging effective mass in strongly correlated systems like $^3$He and MOSFETs, clarifying the diverging mechanism.

Findings

Effective mass diverges near Mott insulators in studied systems.

The divergence fits an extended Brinkman-Rice model.

Over 0.96 correlation strength, the model applies.

Abstract

Emerging devices such as a neuromorphic device and a qubit can use the Mott transition phenomenon, but in particular, the diverging mechanism of the phenomenon remains to be clarified. The diverging-effective mass near Mott insulators was measured in strongly correlated Mott systems such as a fermion $^3$He and a Si metal-oxide-semiconductor-field-effect transistor, and is closely fitted by the effective mass obtained by the extension of the Brinkman-Rice(BR) picture, $m^*/m=1/[1-(U/U_c)^2]=1/(1-{\kappa}^2_{BR}{\rho}^4)$ when ${\kappa}^2_{BR}{\approx}1({\neq}$1), where $0<U/U_c={\kappa}_{BR}{\rho}^2<1$, correlation strength is ${\kappa}_{BR}$, band-filling is ${\rho}$. Its identification is a percolation of a constant mass in the Brinkman-Rice picture. Over ${\kappa}_{BR}{\approx}0.96$ is evaluated.