Abstract: Fluctuations can play an important role in deciding the ultimate fate of a small thermal machine. It is now realized, for example, that the optimization of thermal machines should not only balance power and efficiency but also power fluctuations. In this context, trade-off relations involving the relative fluctuations of currents and the associated entropy production have gathered enormous interest for the past few years in the field of non-equilibrium thermodynamics. In this talk, I will discuss about different classes of thermal machines and point out the impact of relative fluctuations in the performance of machines. I will discuss the universal bounds on the current fluctuations for both continuous and discrete thermal machines and connect our study with the thermodynamic uncertainty relations.

References:
1. Full statistics of non-equilibrium heat and work for many-body quantum Otto engine and universal bounds: A non-equilibrium Green's function approach, Sandipan Mohanta and Bijay Kumar Agarwalla, Phys. Rev. E. 108, 064127 (2023).
2. Precision bound in periodically modulated continuous quantum thermal machines, A. Das, S. Mahunta, Bijay Kumar Agarwalla, and V. Mukherjee, Phys. Rev. E. 108, 014137 (2023).
3. Universal bounds on fluctuations in continuous thermal machines, S. Saryal, M. Gerry, I. Khat, D. Segal, and Bijay Kumar Agarwalla, Phys. Rev. Lett, 127, 190603 (2021).