Gupta Anshu, Silotia Harsha, Kumari Anamika, Dumen Manish, Goyal Saveena, Tomar Ruchi, Wadehra Neha, Ayyub Pushan, Chakraverty Suvankar
Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India.
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India.
Adv Mater. 2022 Mar;34(9):e2106481. doi: 10.1002/adma.202106481. Epub 2022 Jan 18.
Long after the heady days of high-temperature superconductivity, the oxides came back into the limelight in 2004 with the discovery of the 2D electron gas (2DEG) in SrTiO (STO) and several heterostructures based on it. Not only do these materials exhibit interesting physics, but they have also opened up new vistas in oxide electronics and spintronics. However, much of the attention has recently shifted to KTaO (KTO), a material with all the "good" properties of STO (simple cubic structure, high mobility, etc.) but with the additional advantage of a much larger spin-orbit coupling. In this state-of-the-art review of the fascinating world of KTO, it is attempted to cover the remarkable progress made, particularly in the last five years. Certain unsolved issues are also indicated, while suggesting future research directions as well as potential applications. The range of physical phenomena associated with the 2DEG trapped at the interfaces of KTO-based heterostructures include spin polarization, superconductivity, quantum oscillations in the magnetoresistance, spin-polarized electron transport, persistent photocurrent, Rashba effect, topological Hall effect, and inverse Edelstein Effect. It is aimed to discuss, on a single platform, the various fabrication techniques, the exciting physical properties and future application possibilities of this family of materials.
在高温超导令人兴奋的日子过去很久之后,氧化物在2004年因在SrTiO(STO)中发现二维电子气(2DEG)以及基于它的几种异质结构而再度成为焦点。这些材料不仅展现出有趣的物理特性,还在氧化物电子学和自旋电子学领域开辟了新的前景。然而,最近很多关注转向了KTaO(KTO),一种具有STO所有“良好”特性(简单立方结构、高迁移率等)但具有更大自旋轨道耦合这一额外优势的材料。在这篇对迷人的KTO世界的前沿综述中,试图涵盖所取得的显著进展,特别是在过去五年中的进展。还指出了某些未解决的问题,同时提出了未来的研究方向以及潜在应用。与基于KTO的异质结构界面处捕获的2DEG相关的物理现象范围包括自旋极化、超导性、磁阻中的量子振荡、自旋极化电子输运、持续光电流、 Rashba效应、拓扑霍尔效应和逆埃德尔斯坦效应。目的是在一个单一平台上讨论这类材料的各种制造技术、令人兴奋的物理特性以及未来的应用可能性。