Regensburg 2025 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 47: Fluctuations, Noise and Other Transport Topics (joint session TT/DY)

TT 47.11: Talk

Thursday, March 20, 2025, 17:45–18:00, H31

Tunable nonlinear Duffing response of a driven carbon nanotube nanomechanical resonator — •Akong Loh, Furkan Özyigit, Fabian Stadler, Katrin Burkert, Niklas Hüttner, and Andreas K. Hüttel — Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany

Extremely lightweight and with very high quality factors, Carbon nanotube nanomechanical resonators have been used as ultrasensitive force, mass, and charge sensors [1-5]. When suspended on source and drain leads and gated, a CNT nanomechanical resonator can also be operated as a quantum dot. The motion of the nanotube is strongly coupled to single electron tunneling, dominating the nonlinear response [1-5]. Control of the strong nonlinear dynamics of a CNT will be useful for engineering mechanical qubits with information stored in the vibrations and mechanical Schrödinger’s cat states [3]. Here, we analyze the nonlinear vibrational response of a driven CNT quantum dot, at ∼10mK in a dilution refrigerator and with opaque tunnel barriers to minimize dissipation. We demonstrate how the nonlinearity parameters of the coupled system can be controlled via Coulomb blockade and the associated gate voltage, leading to a rich interplay of frequency, damping, and Duffing behavior.
[1] A. K. Hüttel et al., Nano Lett. 9, 2547 (2009).
[2] G. A. Steele et al., Science 325, 1103 (2009).
[3] C. Samanta et al, Nat. Phys. 19, 1340 (2023).
[4] S. Blien et al., Nat. Commun. 11, 1636 (2020).
[5] N. Hüttner et al., Phys. Rev. Appl. 20, 064019 (2023).

Keywords: Carbon nanotubes; Nanomechanics; Nonlinear dynamics; Coulomb blockade