Regensburg 2022 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 35: Quantum Chaos and Coherent Dynamics

DY 35.6: Vortrag

Mittwoch, 7. September 2022, 17:00–17:15, H20

Metastability and quantum coherence-assisted sensing in interacting parallel quantum dots — •Stephanie Matern¹, Katarzyna Macieszczak², Simon Wozny¹, and Martin Leijnse¹ — ¹NanoLund and Solid State Physics, Lund University, Box 118, 22100 Lund, Sweden — ²TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave., Cambridge CB3 0HE, United Kingdom

We study the transient dynamics of two interacting parallel quantum dots weakly coupled to macroscopic leads to gain access to the non-equilibrium transport properties. The stationary state current of this quantum system is known to be sensitive to perturbations much smaller than any other energy scale in the system, specifically compared to the system-lead coupling and the temperature. We show that this is due to a bistable point which leads to a regime in the dynamics where the system exhibits metastability and the dynamics is described as classical dynamics between two metastable phases. The competition of those two metastable phases explain the sensitive behaviour of the stationary current towards small perturbations. We show that this behaviour bears the potential of utilizing the parallel dot as charge sensor which makes use of the quantum coherence effects to achieve a high sensitivity that is not limited by temperature. We analyse the sensitivity in terms of the current signal to noise ratio and find that the parallel dots outperform an analogous single dot setup for a wide range of parameters.