Towards spin-orbit coupling effect in strong electron correlation systems - Denis Maryenko, RIKEN Center

10.06.2021 08:45 – 09:30

Towards spin-orbit coupling effect in strong electron correlation systems
Denis Maryenko
RIKEN Center for Emergent Matter Science, Japan

Oxide compounds constitute a wide material class featuring a wealth of quantum phenomena and functionalities governed by the interplay of various degrees of freedom and electron correlation effects [1, 2]. Particularly, materials with a relativistic spin-orbit coupling interaction (SOI), that couples electron’s spin with its momentum, are nowadays in the spotlight. Large SOI affects both electronic and magnetic structure and is anticipated to lead to the emergence of novel electronic quantum phases laying the ground to future technologies. Thereby, the control of materials and their interfaces is inevitable to unravel the material fundamentals. A serious leap forward has been achieved in epitaxial control of oxide thin films, that lead to the observation of the quantum Hall effects in ZnO and SrTiO3, testimony of a high interface quality [3, 4, 5].
In this talk, I will discuss a surprising observation of the SOI in a high mobility two-dimensional electron system of ZnO heterostructures [6]. It constitutes perhaps one of the tantalizing aspects of reach spin physics found in ZnO [7, 8]. Striking here is that the SOI appears in the regime of strong Coulomb interaction. In fact, the SOI can profoundly compete against Coulomb interaction, which could lead to the emergence of unconventional electronic and spin phases [9]. Thus, the SOI observation unravels another facet of emerging phenomena in ZnO and marks ZnO as an appealing platform enabling to explore the interplay between correlation effects and the spin-orbit coupling, one of the outstanding problems in modern solid state physics. Furthermore, I will present the recent activities and give an outlook for the novel oxide tantalate material platform, exploiting strong SOI and strong electron correlation effects. I will show that the oxide tantalates offer a fruitful platform not only for the fundamental research but also for applications.

References:
[1] Interface physics in complex oxide heterostructures. P. Zubko et al., Annu. Rev. Condens. Matter
Phys. 2, 121 (2011).
[2] Emergent Phenomena at oxide interfaces, H. Y. Hwang et al., Nat. Materials 11, 103 (2012).
[3] Quantum Hall effect in polar oxide heterostructures. A. Tsukazaki et al., Science 315, 388 (2007).
[4] Observation of the quantum Hall effect in -doped SrTiO3. Y. Matsubara et al.,
Nature Communications 7, 11631 (2016).
[5] Quantization of Hall resistance at the metallic interface between an oxide insulator and SrTiO3.
F. Trier et al., Phys. Rev. Lett. 117, 096804 (2016).
[6] Interplay of spin-orbit coupling and Coulomb interaction in ZnO-based electron system.
D. Maryenko et al., accepted in Nature Communications 2021. arXiv: 2010.02461.
[7] Observation of anomalous Hall effect in a non-magnetic two-dimensional electron system.
D. Maryenko et al., Nature Communications 8, 14777 (2017).
[8] Spin-selective electron quantum transport in nonmagnetic MgZnO/ZnO-heterostructures.
D. Maryenko et al., Phys. Rev. Lett. 115, 197601 (2015).
[9] Correlated quantum phenomena in the strong spin-orbit regime. W. Witczak-Krempa et al.,
Annu. Rev. Condens. Matter Phys. 5, 57 (2014).

Lieu

By Zoom Meeting

entrée libre

Fichiers joints

image.png

2.5 Kb