ELFT HÍRADÓ

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

SZFI SeminarThore PosskeUniversity of Hamburg (host: Rózsa 
Levente)Hybridizing Machida-Shibata states - a route to topological 
superconductivity in symmetry class DIII?Tuesday, 21 October 2025, 10:00, 
KFKI Campus, Bldg. 1, 2nd floor, Conference RoomRecently, the Machida-Shibata 
states, which are surface states with an unusual weak coupling to a 
superconducting bulk, have been realized in Ag-corrals on Ag islands on 
superconducting Nb [1]. These time reversal invariant in-gap states, which 
represent the elemental form of a proximity gapped electronic state, form a 
new building block for in-gap topological electronic matter in symmetry class 
DIII. Intriguingly, symmetry class DIII has rigorously been shown not to 
exhibit topologically nontrivial phases in the proximity-coupling setup. By 
considering a small intra-corral electron interaction, we circumvent the no 
go theorem and theoretically demonstrate the hybridization of Machida-Shibata 
states to topologically nontrivial chains with pairs of Majorana modes at 
their ends, which are protected from mutual scattering by time-reversal 
symmetry [2].Special emphasis is given on symmetry classification and the 
spectral peculiarities of this phase, which host vast regions of momenta with 
flat dispersion.[1] https://www.nature.com/articles/s41586-023-06312-0 [2] 
https://arxiv.org/abs/2504.08674 Minden érdeklődőt szívesen látunk! - 
Everyone is welcome to attend.Attila Nagysem-admin AT szfki.hu