Berlin 2024 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 57: Topology: Poster
TT 57.22: Poster
Mittwoch, 20. März 2024, 15:00–18:00, Poster E
Topological phase diagram of the s-d–Hubbard model on finite clusters — •Christian Jöns — Max-Planck-Institut für Struktur und Dynamik der Materie, Hamburg, Germany
Topological concepts in solid-state physics are widely used and applied, e.g., to classify topological insulators. Furthermore, these concepts allow to better understand the famous quantum-Hall effect. The state of quantum-Hall systems with broken time-reversal symmetry is described by the quantized Chern number, a topological invariant. A nonzero Chern number also implies the existence of protected edge states which are observable experimentally.
Here, we consider topological classification starting from an intrinsic parameter manifold different from the reciprocal space. We study interacting electron systems with local spin exchange coupled to the S2 and products of S2. These manifolds represent the configuration spaces of a single or several impurity spins assumed as classical vectors. Topological classification of the s-d–Hubbard model on finite clusters in different geometries is achieved by means of the Nth spin-Chern number. Phase diagrams in the Hubbard-U – exchange-coupling-J plane are computed and discussed. With an analytical relation between the linear response and the spin-Chern number we can look for new insights of < ŝ > (S), with S ∈ S2.