2 papers
quant-ph2026
The geometry of the Hermitian matrix space and the Schrieffer--Wolff transformation
GergŠPintér, György Frank, Dániel Varjas +1
In quantum mechanics, the Schrieffer--Wolff (SW) transformation (also called quasi-degenerate perturbation theory) is known as an approximative method to reduce the dimension of th…
cond-mat.mes-hall2024
Stability of Weyl node merging processes under symmetry constraints
Gabriele Naselli, György Frank, Dániel Varjas +4
Changes in the number of Weyl nodes in Weyl semimetals occur through merging processes, usually involving a pair of oppositely charged nodes. More complicated processes involving m…