Regensburg 2022 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 2: Nanotubes, Nanoribbons and Graphene

TT 2.5: Vortrag

Montag, 5. September 2022, 10:30–10:45, H22

Quantum interference in graphene influenced by dynamic strain — •Christian Glasenapp, Pai Zhao, Marta Prada, Lars Tiemann, and Robert h. Blick — Center for Hybrid Nanostructures, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany

We exploit surface acoustic waves (SAW) as a time-dependent strain wave that propagates through graphene [1] and study its influence on the weak localization (WL) phenomenon at 4 Kelvin. WL is a quantum interference effect that occurs due to the wave nature of charge carriers. In the case of graphene, it can be characterized by inelastic scattering and elastic inter- and intravalley scattering [2]. We fabricated interdigital transducers (IDTs) on a piezoelectric LiNbO₃ substrate, which can be actuated by a radiofrequency (RF) signal to generate a SAW. A large sheet of CVD-grown monolayer graphene was transferred onto the substrate and a Hall bar was patterned in the path of the SAW. In low-field magnetotransport measurements without SAW we observe a well-defined WL effect. When we launch a SAW that strains the graphene layer, WL becomes progressively suppressed with increasing SAW intensity. In this presentation we will show how SAW-induced dynamic strain affects the scattering mechanisms of WL.

[1] P. Zhao et al., Appl. Phys. Lett. 116, 103102 (2020)

[2] E. McCann et al., Phys. Phys. Lett. 97, 146805 (2006)