Cheolhee Han

Tel Aviv University, Israel

15 Jun 2023 Thu 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Entropy is one of the fundamental quantities in physics that quantifies the degrees of freedom of the systems. In certain strongly correlated systems, such as topological superconductors or multi-channel Kondo systems, the presence of strong correlations leads to the appearance of fractional entropy, such as 1/2 log(2). The fractional entropy is a signature of nonlocal degrees of freedom, such as Majorana zero modes or more exotic non-Abelian anyons. However, in the mesoscopic quantum systems hosting these excitations, direct entropy measurements remain highly challenging. One promising approach utilizes Maxwell relations to extract entropy changes from charge measurements. In this talk, applying this approach to a metallic quantum dot system, we propose a feasible way to detect the fractional entropy in the two- and three-channel Kondo effects, corresponding to Majorana and Fibonacci zero modes, respectively, by measuring the charge occupation of the dot. Our protocol provides a general route towards a direct extraction of entropy from charge measurements in mesoscopic systems.

  1. measuring exotic entropy in the mesoscopic systems