Chen Yu, D'Antuono Maria, Trama Mattia, Preziosi Daniele, Jouault Benoit, Teppe Frédéric, Consejo Christophe, Perroni Carmine A, Citro Roberta, Stornaiuolo Daniela, Salluzzo Marco
CNR-SPIN, Complesso Univ. Monte S. Angelo, Naples, I-80126, Italy.
Department of Physics, University of Naples Federico II, Complesso Univ. Monte S. Angelo, Naples, I-80126, Italy.
Adv Mater. 2025 Jan;37(1):e2410354. doi: 10.1002/adma.202410354. Epub 2024 Oct 30.
In a 2D electron system (2DES) the breaking of the inversion, time-reversal and bulk crystal-field symmetries is interlaced with the effects of spin-orbit coupling (SOC) triggering exotic quantum phenomena. Here, epitaxial engineering is used to design and realize a 2DES characterized simultaneously by ferromagnetic order, large Rashba SOC and hexagonal band warping at the (111) interfaces between LaAlO, EuTiO, and SrTiO insulators. The 2DES displays anomalous quantum corrections to the magneto-conductance driven by the time-reversal-symmetry breaking occurring below the magnetic transition temperature. The results are explained by the emergence of a non-trivial Berry phase and competing weak anti-localization/weak localization back-scattering of Dirac-like fermions, mimicking the phenomenology of gapped topological insulators. These findings open perspectives for the engineering of novel spin-polarized functional 2DES holding promises in spin-orbitronics and topological electronics.
在二维电子系统（2DES）中，空间反演、时间反演和体晶体场对称性的破缺与自旋轨道耦合（SOC）的效应相互交织，引发奇异的量子现象。在此，利用外延工程设计并实现了一种2DES，其在LaAlO、EuTiO和SrTiO绝缘体之间的（111）界面处同时具有铁磁序、大Rashba自旋轨道耦合和六角形能带翘曲的特征。该2DES在低于磁转变温度时发生时间反演对称性破缺，从而对磁电导表现出反常量子修正。这些结果可通过非平凡Berry相的出现以及类狄拉克费米子的竞争弱反局域化/弱局域化背散射来解释，这类似于带隙拓扑绝缘体的现象学。这些发现为新型自旋极化功能2DES的工程设计开辟了前景，有望应用于自旋轨道电子学和拓扑电子学领域。
