Subband Structure of a Two-Dimensional Electron Gas Formed at the Polar Surface of the Strong Spin-Orbit Perovskite KTaO3

King, P.D.C.

关键词: CONFINEMENT;    ELECTRON GAS;    OXIDES;    PEROVSKITE;    PHOTOEMISSION;    SPIN;    TRANSPORT MATSCI;    PHYS;   

DOI  :  10.2172/1035804
RP-ID  :  SLAC-PUB-14625
PID  :  OSTI ID: 1035804
Others  :  TRN: US201206%%18

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

We demonstrate the formation of a two-dimensional electron gas (2DEG) at the (100) surface of the 5d transition-metal oxide KTaO{sub 3}. From angle-resolved photoemission, we find that quantum confinement lifts the orbital degeneracy of the bulk band structure and leads to a 2DEG composed of ladders of subband states of both light and heavy carriers. Despite the strong spin-orbit coupling, we find no experimental signatures of a Rashba spin splitting, which has important implications for the interpretation of transport measurements in both KTaO{sub 3}- and SrTiO{sub 3}-based 2DEGs. The polar nature of the KTaO{sub 3}(100) surface appears to help mediate formation of the 2DEG as compared to non-polar SrTiO{sub 3}(100).