Speaker
Description
Trapped ions confined in radiofrequency traps offer an excellent degree of control, in terms of unitary operations, initialization and readout. Furthermore, advanced techniques can be employed to control external (motional) degrees of freedom. Complementing the toolbox with non-unitary operations such depolarization channels or controlled coupling to microscopic environments (ancillas) renders trapped-ion platforms ideal for studying concepts from microscopic and quantum thermodynamics.
In this talk, we show the realization of a single-ion spin heat engine, where the work agent is a controlled two-level system. Coupling to heat baths is emulated via controlled incomplete optical pumping. An oscillatory degree of free serves as a flywheel, where energy generated by the engine operation is deposited. We study the deposition process via quantum state tomography on the flywheel, showing the useful fraction of the deposited energy – the ergotropy – is inherently limited by intrinsic work fluctuations [1].
We also show results from a recently completed experiment, where heat leaks occurring throughout the unitary evolution of two trapped-ion qubits are detected using the frameworks of global passivity [2] and passivity deformation [3]. We demonstrate that both approaches can detect heat leaks with a sensitivity beyond the microscopic version of the 2nd law, and that passivity deformation is more sensitive as compared to global passivity [4].
[1] D. von Lindenfels et al. Phys. Rev. Lett. 123, 080602 (2019)
[2] R. Uzdin & S. Rahav, Phys. Rev. X 8, 021064 (2018)
[3] R. Uzdin & S. Rahav, PRX Quantum 2, 010336 (2021)
[4] D. Pijn et al., arXiv:2110.03277
