The interplay of ferroelectricity and magneto-transport in non-magnetic moir\'{e} superlattices

TL;DR

This study demonstrates room-temperature ferroelectricity in graphene/hBN moiré superlattices, where ferroelectric polarization is enhanced by magnetic fields and influences quantum transport, revealing potential for 2D multifunctional devices.

Contribution

It uncovers electronic ferroelectricity in non-magnetic moiré superlattices and shows magnetic-field-induced enhancement of ferroelectric polarization affecting quantum transport.

Findings

Room-temperature ferroelectricity observed in graphene/hBN moiré superlattices.

Magnetic fields enhance ferroelectric polarization without magnetic elements.

Ferroelectricity modulates quantum transport phenomena like Shubnikov-de Haas oscillations.

Abstract

The coupling of ferroelectricity and magnetic order provides rich tunability for engineering material properties and demonstrates great potential for uncovering novel quantum phenomena and multifunctional devices. Here, we report interfacial ferroelectricity in moir\'{e} superlattices constructed from graphene and hexagonal boron nitride. We observe ferroelectric polarization in an across-layer moir\'{e} superlattice with an intercalated layer, demonstrating a remnant polarization comparable to its non-intercalated counterpart. Remarkably, we reveal a magnetic-field enhancement of ferroelectric polarization that persists up to room temperature, showcasing an unconventional amplification of ferroelectricity in materials lacking magnetic elements. This phenomenon, consistent across devices with varying layer configurations, arises purely from electronic rather than ionic contributions. Furthermore, the ferroelectric polarization in turn modulates quantum transport characteristics, suppressing Shubnikov-de Haas oscillations and altering quantum Hall states in polarized phases. This interplay between ferroelectricity and magneto-transport in non-magnetic materials is crucial for exploring magnetoelectric effects and advancing two-dimensional memory and logic applications.