Gate-tunable electron interaction in high-{\kappa} dielectric films

TL;DR

This paper demonstrates how an external gate can tune the range of Coulomb interactions in high-κ dielectric films, revealing new electrostatic behaviors and enabling studies of topological phase transitions and related phenomena.

Contribution

It uncovers the gate-dependent tuning of Coulomb interaction range in high-κ films, transitioning from logarithmic to dipolar or exponential behavior, and explores implications for topological phases.

Findings

Range of Coulomb interaction can be tuned by gate distance.

Interaction transitions from logarithmic to dipolar or exponential.

Implications for topological phase transitions and memory devices.

Abstract

The two-dimensional (2D) logarithmic character of Coulomb interaction between charges and the resulting logarithmic confinement is a remarkable inherent property of high dielectric constant (high-$\kappa$) thin films with far reaching implications. Most and foremost, this is the charge Berezinskii-Kosterlitz-Thouless transition with the notable manifestation, low-temperature superinsulating topological phase. Here we show that the range of the confinement can be tuned by the external gate electrode and unravel a variety of electrostatic interactions in high-$\kappa$ films. We find that by reducing the distance from the gate to the film, we decrease the spatial range of the 2D long-range logarithmic interaction, changing it to predominantly dipolar or even to exponential one at lateral distances exceeding the dimension of the film-gate separation. Our findings offer a unique laboratory for the in-depth study of topological phase transitions and related phenomena that range from criticality of quantum metal- and superconductor-insulator transitions to the effects of charge-trapping and Coulomb scalability in memory nanodevices.