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arXiv · 1908.04977

Observation of Shubnikov-de Haas Oscillations, Non-trivial Berry Phase, Planar Hall and Anisotropic Magnetoresistance at the conducting interface of EuO-KTaO$_3$

Nand Kumar·Neha Wadehra·Ruchi Tomar·Sushanta Dattagupta·Sanjeev Kumar·S. Chakraverty
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Abstract

The momentum dependent splitting of spin-bands in an electronic system is known as the "Rashba effect". Systems with the "Rashba effect" possess a Dirac point in momentum space. An electron in a cyclotron orbit enclosing that Dirac point in the reciprocal space gains a "Berry phase". We report here the Shubnikov-de-Haas oscillations (SdH) at the conducting interface of EuO-KTaO$_3$ (KTO). Observed SdH oscillations suggest the presence of two Fermi surfaces. For both the Fermi surfaces, we have seen the presence of a non-trivial "Berry phase" suggesting that the surfaces enclose the "Dirac point". Thus the Berry phase originates from the inner and outer Fermi surfaces of the Rashba spin-split bands. As in topological insulators, two fold planar Hall and anisotropic magnetoresistance have also been observed in EuO-KTO. Analyzing the SdH, Hall and magnetoresistance data, we have drawn a possible band diagram near the Fermi surface.

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Nand Kumar, Neha Wadehra, Ruchi Tomar, Sushanta Dattagupta, Sanjeev Kumar, S. Chakraverty. 2019-08-14. Observation of Shubnikov-de Haas Oscillations, Non-trivial Berry Phase, Planar Hall and Anisotropic Magnetoresistance at the conducting interface of EuO-KTaO$_3$. https://arxiv.org/abs/1908.04977

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