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DY: Fachverband Dynamik und Statistische Physik

DY 21: Focus Session: Nanomechanical Systems for Classical and Quantum Sensing I (joint session TT/DY/HL/QI)

DY 21.3: Talk

Tuesday, March 19, 2024, 12:15–12:30, H 3007

Cavity optomechanics with carbon nanotube quantum dots — •Akong N. Loh, Furkan Özyigit, Fabian Stadler, Niklas Hüttner, and Andreas K. Hüttel — Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany

Carbon nanotubes (CNTs) are the smallest and lightest nanomechanical beam resonators. When suspended transversally between two electrodes (Ti/Au for example) and then gated, they can act as mechanical beam resonators with large quality factors and also as quantum dots. The motion of a CNT is coupled to other degrees of freedom, such as photons, spins, and electrons. The optomechanical coupling of a single wall carbon nanotube nanomechanical resonator to a microwave cavity has been realized and quantified through optomechanically induced transparency measurements [1]. The quantum dot properties of the CNT were exploited (specifically the nonlinearity of the coulomb blockade) to significantly enhance the coupling strength [1,2]. Current work is directed towards achieving even stronger coupling and possibly groundstate cooling of the nanomechanical resonator through anti-Stokes processes. This requires significant improvement of the microwave cavity, CNT growth and transfer. All measurements are done at ∼10 mK in a dilution refrigerator.

[1] S. Blien et al., Nat. Comm. 11 (2020) 1636

[2] N. Hüttner et al., Phys. Rev. Applied, in press (2023), arXiv:2304.02748

Keywords: Optomechanics; Carbon nanotubes; Microwave cavity; Quantum dot; Mechanical resonator