Benoit Douçot
(LPTHE, CNRS and Sorbonne University)

 
Abstract:
Recent experiments [1] imaging the non-equilibrium current pattern in disordered Chern insulators have shown that most of the Hall current happens to flow inside the bulk of the spectrum, and not on narrow edge channels, contrary to the most common expectation.
I will discuss the role of various ingredients that shape the electrostatic potential and current profiles across such Hall bar systems, including Coulomb interactions, dissipation, smooth external potentials, and disorder. I will argue that the latter two are the most important in the recent experiments reported in [1]. In collaboration with D. Kovrizhin and R. Moessner, we have found that they can induce wide meandering conduction channels, that carry the quantized Hall current within the bulk of the system [2].

^[1] G. M. Ferguson et al, Nature materials 22, 1100 (2023)
^[2] B. Doucot, D. Kovrizhin, R. Moessner, PNAS 121, No. 39 (2024)

Zoom registration link:
https://zoom.us/meeting/register/q5hnI3NOTTujBQRYE7iZtA