论文标题
巨大的Rashba旋转旋转分裂在紧张的KTAO3超薄膜中用于圆形光藻电流
Giant Rashba spin splitting in strained KTaO3 ultrathin films for circular photogalvanic currents
论文作者
论文摘要
表面和界面的强大RASHBA效应引起了人们对基本科学探索和实际应用的极大关注。在这里，第一原则的调查表明，通过施加双轴压力，可以在KTAO $ _3 $（KTO）超薄膜中实现巨大而可调的Rashba效应。当将平面压缩应变增加到-5 \％时，RashBA旋转分裂能量达到$ e_ {r} = 140 $ MEV，大约对应于rashba耦合常数$α__{r} = 1.3 $evÅ。我们研究了其应变依赖性的晶体结构，能带和相关特性，从而阐明了巨型Rashba效应的机制。此外，我们表明可以在Srtio $ _3 $封盖层和/或SI底物的情况下保持巨大的Rashba旋转分裂，并且可以实现强大的圆形光负效应，以在KTO薄膜或相关的杂物结构中产生自旋极光电流，这是对未来的Spintronic spintronic and Spintronic and Spintronic and Spintronic and Eptoelectronic and optoelectronic和optoelectronic和optoelectronic和optoelectronic and corments的效果。
Strong Rashba effects at surfaces and interfaces have attracted great attention for basic scientific exploration and practical applications. Here, the first-principles investigation shows that giant and tunable Rashba effects can be achieved in KTaO$_3$ (KTO) ultrathin films by applying biaxial stress. When increasing the in-plane compressive strain nearly to -5\%, the Rashba spin splitting energy reaches $E_{R}=140$ meV, approximately corresponding to the Rashba coupling constant $α_{R}=1.3$ eV Å. We investigate its strain-dependent crystal structures, energy bands, and related properties, and thereby elucidate the mechanism for the giant Rashba effects. Furthermore, we show that giant Rashba spin splitting can be kept in the presence of SrTiO$_3$ capping layer and/or Si substrate, and strong circular photogalvanic effect can be achieved to generate spin-polarized currents in the KTO thin films or related heterostructures, which are promising for future spintronic and optoelectronic applications.
