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

King, P.D.C.

SLAC National Accelerator Laboratory

关键词: Perovskite;    36 Materials Science;    Electron Gas;    Matsci, Phys;    Oxides;   

DOI  :  10.2172/1035804
RP-ID  :  SLAC-PUB-14625
RP-ID  :  AC02-76SF00515
RP-ID  :  1035804

美国|英语

来源: UNT Digital Library

【 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).