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TT: Fachverband Tiefe Temperaturen

TT 57: Topology: Poster

TT 57.18: Poster

Wednesday, March 20, 2024, 15:00–18:00, Poster E

Topology of open spin chains — •Alexander Sattler and Maria Daghofer — Institut für Funktionelle Materie und Quantentechnologien, Universität Stuttgart, 70550 Stuttgart, Germany

Some spin chains, for example the Haldane chain or a topological dimerized chain, feature topologically protected edge states that are robust against some kind of noise. Despite their great appeal such spin states have not yet been created in a controlled manner in solid states environments, as spin chains on surfaces, where such a robustness can be quantified. We are here interested in the robustness of edge states against the coupling with surface.

Beyond that, since no physical system is perfectly isolated, it is of general interest to study whether the topological robustness is still given if there is a coupling with an environment.

The theoretical investigation is based on an alternating Heisenberg spin chain with spin-1/2, which is investigated by means of exact diagonalization. The coupling with the environment is modeled with the Lindblad-Master equation, whereby the jump operators are chosen in such a way that decoherence and spin flips occur.

We find, that the analyzed topological spin chain is susceptible to coupling with an environment just like topologically trivial spin chains. This can be seen in the time evolution of e.g. the topological energy gap, entropy, fidelity and edge state magnetization.

Keywords: Open quantum systems; Decoherence; Topology; Heisenberg spin chain; Lindblad Master equation