Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 3: Quantum Dots and Wires: Transport

HL 3.6: Talk

Monday, March 18, 2024, 11:15–11:30, EW 202

Study of non-linear dynamics of a nanomechanical resonator with single-electron tunneling — •Sofia Sevitz¹, Kushagra Aggarwal², Janet Anders^1,3, and Natalia Ares⁴ — ¹University of Potsdam, Institute of Physics and Astronomy, 14476 Potsdam, Germany — ²Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom — ³Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom — ⁴Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom

Devices that present non-linear behaviour are of much interest for their broad applications ranging from thermodynamics, chaos to metrology. A promising platform is a suspended Carbon Nanotube (CNT) containing an electrostatically defined quantum dot. The electronic transport couples to the mechanical degrees of freedom of the CNT. When the coupling is in the ultrastrong regime, the CNT experiences a pronounced back-action that leads to non-linear dynamics. When the CNT is driven weakly, this non-linearity is presented as a softening of the resonance frequency of the CNT. However, when the CNT is subjected to a strong driving, intrinsic non-linearities of the mechanics take over. The main feature is the emergence of arch-like resonances in the electronic transport. In this talk, we describe our physical model that captures the combined interplay between the intrinsic non-linearities of the mechanics (modeled as a Duffing oscillator) and the electromechanical coupling under different driving regimes. Finally, we show that our model is in good agreement with our experimental electron transport measurements.

Keywords: Nanoelectromechanical system; Ultrastrong electromechanical coupling; Non-linear dynamics; Quantum device