The JCMS series

The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.

October 14th, 2024: Sreenath Manikandan

On Monday, October 14th, 2024 from 11 am to 12 am we will host a seminar by Sreenath Manikandan from Nordita.

Title

Principles of quantum refrigeration and thermodynamic control in the nanoscale

Abstract

Cooling below ~10 mK, typical ambient temperatures that can be reached in current dilution refrigerators, can significantly enhance various quantum technologies, from single photon detectors to quantum sensors. I will present an overview of some recent theoretical results in this field using solid-state quantum devices, based on (1) the principle of adiabatic magnetization of superconductors and (2) energy filtering offered by quantum thermoelectrics. These devices can in principle start working from the base temperature of current dilution refrigerators and generate substantial cooling power/achieve up to one order of magnitude further cooling. I will discuss the thermodynamics of these devices and conclude my talk by discussing a closely connected open problem, which is the management of excess heat generated in quantun circuits. I will present a simple example where the excess heat generated in quantum circuits can be recycled as a fuel for achieving a pre-determined distribution of heat currents across a chain of electronic nano-cavities. Such efficient thermodynamic control schemes can significantly improve the performance of quantum technologies in solid-state, where lack of control over excess charge and heat currents can pose major challenges to progress.

Fig. 1: (University of Rochester illustrations / Micheal Osadciw).


References

[1] “Autonomous quantum absorption refrigerators.” Sreenath K. Manikandan, Étienne Jussiau, and Andrew N. Jordan. Physical Review B (2020) 102, no. 23: 235427.

[2] “Thermal control across a chain of electronic nanocavities.” Étienne Jussiau, Sreenath K. Manikandan, Bibek Bhandari, and Andrew N. Jordan. Physical Review B (2021) 104, no. 4: 045414.

[3] “Superconducting quantum refrigerator: Breaking and rejoining Cooper pairs with magnetic field cycles.” Sreenath K. Manikandan, Francesco Giazotto, and Andrew N. Jordan. Physical Review Applied (2019) 11, no. 5: 054034.

[4] “Cyclic superconducting refrigerators using guided fluxon propagation.” Tathagata Karmakar, Étienne Jussiau, Sreenath K. Manikandan, and Andrew N. Jordan. Physical Review Research (2024) 6, no. 1: 013085.