Regensburg 2025 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 4: 2D Materials and their Heterostructures II (joint session DS/HL)

DS 4.2: Vortrag

Dienstag, 18. März 2025, 10:00–10:15, H3

Proximity-induced spin-orbit coupling in bilayer graphene quantum wires — •Michael Laumer and Angelika Knothe — Universität Regensburg, 93053 Regensburg, Germany

The gate-tuneable band gap and the possibility to tailor its band structure by proximitizing with other 2D materials [1] make bilayer graphene (BLG) an excellent platform for future quantum technologies. By applying spatially modulated displacement fields, one may confine BLG’s charge carriers into electrostatically induced nanostructures [2, 3]. Proximitizing the BLG with a transition metal dichalcogenide (TMDC) strongly enhances the SOC of the adjoining graphene layer [1]. Fascinated by the concept of proximity-tailoring BLG nanostructures, we convey the idea of proximity-inducing SOC to a gate-confined BLG quantum wire. We theoretically study the resulting quantized subband structure for different SOC strengths and as a function of the wire geometry. Our results help us understand how proximity-induced SOC manifests in confined geometries and identify different regimes of the wires’ electronic properties.

[1] K. Zollner, M. Gmitra, and J. Fabian. Swapping exchange and spin-orbit coupling in 2d van der waals heterostructures. Phys. Rev. Lett., 125:196402, (2020). [2] A. Knothe and V. Fal’ko. Influence of minivalleys and berry curvature on electrostatically induced quantum wires in gapped bilayer graphene. Phys. Rev. B, 98:155435, (2018). [3] H. Overweg et al. Topologically nontrivial valley states in bilayer graphene quantum point contacts. Phys. Rev. Lett., 121:257702, (2018).

Keywords: bilayer graphene; spin-orbit coupling; quantum wires