[Speaker]: Gentaro Watanabe (Zhejiang University)

[Date]: June 1st, 16:00 (jpn time)

[Style]: Webinar via zoom

[Title]: Quantum performance of microscopic heat engines under outcoupling

[Abstract]:

Advances in technology so far have enabled us to downsize the heat engines and recent development spurred the fabrication of heat engines at the submicron to nanoscale. Especially in the last decade, great attention has been paid to so-called quantum heat engines (QHEs), microscopic heat engines whose working substance is a quantum system [1, 2, 3].

While the performance of QHEs are commonly accessed for a single isolated engine for a single cycle, their actual performance when they are coupled to an external system to extract work is a non-trivial and important issue since QHEs are susceptible to the outcoupling due to their smallness. For the last few years, we are interested in quantum effects emerging in the performance of outcoupled QHEs [4, 5]. What we have found is that, when multiple indistinguishable bosonic QHEs are coupled to an external system, the internal energy change of the external system exhibits an enhancement arising from permutation symmetry in the ensemble, which is absent when the latter consists of distinguishable engines [5]. We have also found that, when a QHE undergoes an operation over multiple cycles, the total energy change in the external system performed by the engine need not be proportional to the number of cycles [4].

References

[1] H. E. D. Scovil and E. O. Schulz-DuBois, Phys. Rev. Lett. 2, 262 (1959).

[2] R. Alicki, J. Phys. A: Math. Gen. 12, L103 (1979).

[3] R. Kosloff, J. Chem. Phys. 80, 1625 (1984).

[4] G. Watanabe, B. P. Venkatesh, P. Talkner, and A. del Campo, Phys. Rev. Lett. 118, 050601 (2017).

[5] G. Watanabe, B. P. Venkatesh, P. Talkner, M.-J. Hwang, and A. del Campo, arXiv:1904.07811 (to appear in Phys. Rev. Lett.).