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arXiv · 2206.03843

A multiferroic two-dimensional electron gas

Julien Bréhin·Yu Chen·Maria D'Antuono·Sara Varotto·Daniela Stornaiuolo·Cinthia Piamonteze·Julien Varignon·Marco Salluzzo·Manuel Bibes
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Abstract

Multiferroics are compounds in which at least two ferroic orders coexist - typically (anti)ferromagnetism and ferroelectricity. While magnetic order can arise in both insulating and conducting compounds, ferroelectricity is in principle not allowed in metals although a few two-dimensional (semi)metals were reported to behave as ferroelectrics. Yet, the combination with magnetic order to realize multiferroic metals remains elusive. Here, by combining x-ray spectroscopy and magnetotransport, we show the coexistence of ferroelectricity and magnetism in an oxide-based two-dimensional electron gas (2DEG). The data evidence a non-volatile switching of the polar displacements and of the anomalous Hall effect by the polarization direction, demonstrating a magnetoelectric coupling. Our findings provide new opportunities in quantum matter stemming from the interplay between ferroelectricity, ferromagnetism and Rashba spin-orbit coupling in a 2DEG.

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Julien Bréhin, Yu Chen, Maria D'Antuono, Sara Varotto, Daniela Stornaiuolo, Cinthia Piamonteze, Julien Varignon, Marco Salluzzo, Manuel Bibes. 2022-06-08. A multiferroic two-dimensional electron gas. https://arxiv.org/abs/2206.03843

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