21 citations · 33 across the 5 of their papers we have counts for
6 papers
Multifold degeneracy points of quantum systems and singularities of matrix varieties
György Frank, András Pályi, Gergő Pintér +1
Parameter-dependent quantum systems often exhibit energy degeneracy points, whose comprehensive description naturally lead to the application of methods from singularity theory. A…
The geometry of the Hermitian matrix space and the Schrieffer--Wolff transformation
Gergő Pintér, 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…
Singularity theory of Weyl-point creation and annihilation
György Frank, Gergő Pintér, András Pályi
Weyl points (WP) are robust spectral degeneracies, which can not be split by small perturbations, as they are protected by their non-zero topological charge. For larger perturbatio…
Birth Quota of Non-Generic Degeneracy Points
Gergő Pintér, György Frank, Dániel Varjas +1
Weyl points are generic and stable features in the energy spectrum of Hamiltonians that depend on a three-dimensional parameter space. Non-generic isolated two-fold degeneracy poin…
Magnetic degeneracy points in interacting two-spin systems: geometrical patterns, topological charge distributions, and their stability
György Frank, Zoltán Scherübl, Szabolcs Csonka +2
Spectral degeneracies of quantum magnets are often described as diabolical points or magnetic Weyl points, which carry topological charge. Here, we study a simple, yet experimental…
Observation of spin-orbit coupling induced Weyl points and topologically protected Kondo effect in a two-electron double quantum dot
Zoltán Scherübl, András Pályi, György Frank +8
Recent years have brought an explosion of activities in the research of topological aspects of condensed-matter systems. Topologically non-trivial phases of matter are typically ac…