PGI-1 Talk: Dr. Luis Canonico

Quantum Theory of Materials Seminar

Real-space Calculation of Orbital Responses in Disordered Materials

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Meeting ID: 365 955 613 323
Passcode: ND3Lr3NK

The orbital-Hall effect (OHE) refers to the transverse flow of orbital angular momentum due to a longitudinally applied electric field. The seminal works of Bernevig et al. [1] and Kontani et al. [2] predicted its existence under nonequilibrium situations, and it was demonstrated that these responses are sizable in systems with quenched orbital character [3]. Recently two experimental groups independently confirmed its existence through magneto-optical Kerr rotation measurements in Ti [4] and Cr [5]. To date, most of those experimental results on the electrical generation of orbital currents and their application concentrate on three-dimensional (3D) systems. Nonetheless, the tunability in the properties of two-dimensional (2D) materials and the prospect of developing ultra-compact light-metal-based orbitronic devices has gained significant attention. For instance, theoretical works predicted that 1H transition metal dichalcogenides (TMDs) could host orbital-Hall insulating phases [6-7] characterized by an orbital Chern number and in-gap OAM-carrying edge states and beyond TMDs [8]; phosphorene was also identified as a suitable platform for unambiguous detection of orbital signals [9].

However, despite all the theoretical and experimental development, for practical applications of orbitronics, it is critical to understand the role of the disorder, which is inherent to the fabrication of any device in the generation and relaxation of orbital currents and nonequilibrium densities. In my talk, I will revisit the orbital angular momentum transport in insulating 2D transition metal dichalcogenides. In addition, I will present our new efficient linear-scaling method that allows the real-space computation of the orbital Hall conductivity and other electrical orbital responses in disordered materials from the Berry phase theory of magnetization [10] in systems approaching experimentally relevant scales and geometries.

[1] Bernevig, B. A., Hughes, T. L., & Zhang, S. C Physical Review Letters, 95(6), 066601 (2005).
[2] Kontani, H., Tanaka, T., Hirashima, D. S., Yamada, K., & Inoue, J. Physical review letters, 102(1), 016601.
[3] Go, D., Jo, D., Kim, C., & Lee, H. W. Physical Review Letters, 121(8), 086602 (2018).
[4] Choi, Y.G., Jo, D., Ko, K.H., Go, D., Kim, K.H., Park, H.G., Kim, C., Min, B.C., Choi, G.M. and Lee, H.W., Nature, 619(7968), pp.52-56 (2023).
[5] Lyalin, I., Alikhah, S., Berritta, M., Oppeneer, P. M., & Kawakami, R. K. Physical Review Letters, 131(15), 15670 (2023).
[6] Canonico, L. M., Cysne, T. P., Molina-Sanchez, A., Muniz, R. B., & Rappoport, T. G Physical Review B, 101(16), 161409 (2020).
[7] Bhowal, S., & Satpathy, S. Physical Review B, 102(3), 035409 (2020).
[8] Cysne, T. P., Costa, M., Canonico, L. M., Nardelli, M. B., Muniz, R. B., & Rappoport, T. G. Physical Review Letters, 126(5), 056601 (2021).
[9] Cysne, T. P., Costa, M., Nardelli, M. B., Muniz, R. B., & Rappoport, T. G. Physical Review B, 108(16), 165415 (2023).
[10] Bhowal, S., & Vignale, G. Physical Review B, 103(19), 195309 (2021).

Contact

Dr. Dongwook Go
Phone: +49 2461 61-4399
Email: d.go@fz-juelich.de

Dr. Luis Canonico
Catalan Institute of Nanoscience and Nanotechnology (ICN2),CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
Email: luis.canonico@icn2.cat