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A: Fachverband Atomphysik
A 16: Ultra-cold atoms, ions, and BEC (joint session A/Q)
A 16.3: Poster
Mittwoch, 22. September 2021, 16:30–18:30, P
Single-atom quantum otto motor driven by atomic collisions — •Jens Nettersheim1, Sabrina Burgardt1, Daniel Adam1, Eric Lutz2, and Artur Widera1 — 1Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany — 2Institute for Theoretical Physics I,University of Stuttgart, Stuttgart, Germany
Recent advances in controlling nanoscopic objects suggest the realizations of machines exploiting quantum properties. However, the increasing importance of fluctuations in quantum systems calls into question whether such devices can combine high efficiency, high output power, and small power fluctuations. Experimentally, we realize a stable quantum-Otto engine by immersing single Cs atoms into an ultracold Rb bath. Employing inelastic spin-exchange interactions, we maximize output power while minimizing power fluctuations owing to the finite quantum spin space forming the machine. We investigate the population fluctuations of the system as a function of its heat exchange and output power. For our system with seven quantum-spin levels, the initial and final states are polarized. They show no population fluctuations, in contrast to an infinite-level harmonic oscillator system at a given temperature. We analyze in which parameter range the quantum-spin engine can outperform harmonic oscillator systems in terms of output power and power fluctuations.