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DS: Fachverband Dünne Schichten
DS 7: 2D Materials and their Heterostructures III
DS 7.6: Talk
Wednesday, March 20, 2024, 11:00–11:15, A 053
Electronic structure of intercalated α-NbSi2N4 and α-TaSi2N4 monolayers and their van der Waals heterostructures — •Timon Moško1 and Martin Gmitra1,2 — 1Institute of Physics, Pavol Jozef Šafárik University in Košice, 04001 Košice, Slovakia — 2Juraj Mnich Institute of Experimental Physics, Slovak Academy of Sciences, 04001 Košice, Slovakia
Recent DFT studies of monolayer materials promote intercalated MA2Z4 monolayers as versatile atomically thin materials with a wide spectrum of physical properties. In the talk, we present a first-principles study of the electronic structure of α-NbSi2N4 and α-TaSi2N4 monolayers, as well as their heterostructure. We investigate mechanical stability, charge density wave formation, electronic susceptibility, and magnetic order. We found that the Hubbard on-site on metallic atoms M drives the α-NbSi2N4 from a magnetic conductor to a magnetic insulator and α-TaSi2N4 from a non-magnetic Eliashberg superconductor to a magnetic insulator. Magnetic ground state properties were analyzed using a classical Heisenberg model, providing insights into exchange integrals, magnetocrystalline anisotropy, and critical transition temperatures. Proximity-induced effects in α-NbSi2N4 / α-TaSi2N4 heterostructure uncover lead to the doping effect and emergence of the narrow Ta dz2 hole pocket at the Brillouin zone center susceptible to suggesting its potential as a hybrid system for controlling spin and thermal transport under a transverse electric field.
This work was supported by the APVV SK-CZ-RD-21-0114, FLAG ERA JTC 2021 2DSOTECH, and IMPULZ IM-2021-42 grants.
Keywords: intercalated monolayers; 2D ferromagnetism; first-principles calculations