Km Rubi1,Dumen Manish2,Suvankar Chakraverty2,Mun Chan1,Neil Harrison1
Los Alamos National Laboratory1,Institute of Nano Science and Technology2
Km Rubi1,Dumen Manish2,Suvankar Chakraverty2,Mun Chan1,Neil Harrison1
Los Alamos National Laboratory1,Institute of Nano Science and Technology2
The coexistence of electric-field controlled superconductivity and spin-orbit interaction in two-dimensional electron gas (2DEG) based on complex oxides (e.g., SrTiO<sub>3</sub> and KTaO<sub>3</sub>) hold great promise for advancement in spintronics and quantum computing. However, a comprehensive understanding of the electronic bands that give rise to the multifunctional character of these 2DEGs remains elusive. To address this, we recently investigated quantum oscillations in the magnetoresistance of a KTaO<sub>3</sub>-2DEG in high magnetic fields (60 T).<br/>KTaO<sub>3</sub> is a 5<i>d </i>transition metal oxide, exhibiting a lighter effective mass of electrons and a stronger spin-orbit interaction at its conducting surface/interface than its counterpart SrTiO<sub>3</sub> [1-2]. A high-mobility spin-polarized 2DEG with the superconducting feature is discovered at the EuO/KTaO<sub>3</sub> interface [3]. In this talk, I will present novel insights into the electronic states of the EuO/KTaO<sub>3</sub> interface investigated through Shubnikov-de Haas (SdH) oscillations. Remarkably, we observed a progressive increase in cyclotron mass and oscillation frequency with the magnetic field, indicating the presence of non-trivial electronic bands [4]. Besides providing experimental evidence for topological-like electronic states in KTaO<sub>3</sub>-2DEG, these results shed light on the recent predictions of topological states in the 2DEG based on similar perovskite transition metal oxides.<br/><b>References</b><br/>[1] K. Rubi <i>et al</i>., npj Quantum Materials <b>5</b>, 1 (2020), King, P. D. C. <i>et al</i>. Phys. Rev. Lett. <b>108</b>, 117602 (2012).<br/>[2] K. Rubi <i>et al</i>., Phy. Rev. Research <b>3</b>, 033234 (2021).<br/>[3] H. Zhang <i>et al</i>., Phys. Rev. Lett. <b>121</b>, 116803 (2018), Liu <i>et al</i>., Science <b>371</b>, 716 (2021).<br/>[4] K. Rubi <i>et al</i>., arXiv:2307.04854 (2023).<br/><br/><b>Acknowledgement:</b> We acknowledge support from the National High Magnetic Field Laboratory, supported by the National Science Foundation through NSF/DMR-1644779 and the State of Florida, and the US Department of Energy "Science of 100 Tesla" BES program.