ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarAsbóth JánosHUN-REN Wigner RCP SZFIFloquet-Anderson localization 
in the Thouless pump and how to avoid itTuesday, 12 March 2024, 10:00, KFKI 
Campus, Bldg. 1, 2nd floor, Conference RoomWe investigated numerically how 
onsite disorder affects conduction in the periodically driven Rice-Mele 
model, a prototypical realization of the Thouless pump. Although the pump is 
robust against disorder in the fully adiabatic limit, much less is known 
about the case of finite period time T, which is relevant also in light of 
recent experimental realizations. We found [1] that at any fixed period time 
and nonzero disorder, increasing the system size L→∞ always leads to a 
breakdown of the pump, indicating Anderson localization of the Floquet 
states. Our numerics indicate, however, that in a properly defined 
thermodynamic limit, where L/T^θ is kept constant, Anderson localization can 
be avoided, and the charge pumped per cycle has a well-defined value – as 
long as the disorder is not too strong. The critical exponent θ is not 
universal, rather, its value depends on the disorder strength. Our findings 
are relevant for practical, experimental realizations of the Thouless pump, 
for studies investigating the nature of its current-carrying Floquet 
eigenstates, as well as the mechanism of the full breakdown of the pump, 
expected if the disorder exceeds a critical value.[1] A Grabarits, A Takacs, 
IC Fulga, and JK Asboth,  arXiv:2309.12882 Minden érdeklődőt szívesen 
látunk! - Everyone is welcome to attend.Attila Nagysem-admin AT szfki.hu