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HL: Fachverband Halbleiterphysik

HL 80: Quantum transport and quantum Hall effects

HL 80.2: Vortrag

Freitag, 20. März 2020, 09:45–10:00, POT 51

Model wavefunctions for interfaces between lattice Laughlin states — •Blazej Jaworowski and Anne Nielsen — Max Planck Institut für Physik Komplexer Systeme, 01187 Dresden, Germany

Interfaces between different topological orders, e.g. different fractional quantum Hall states, are predicted to exhibit nontrivial phenomena, such as anyonic Andreev reflection or parafermion zero modes. However, microscopic descriptions of such systems are quite rare, as they are difficult to study using exact diagonalization. In this work we use conformal field theory to construct microscopic model wavefunctions for interfaces between lattice Laughlin states, describing both the ground states and quasihole excitations [1]. We find that requiring trivial mutual statistics of particles on different sides puts a restriction on possible fillings, coinciding with a similar condition based on K-matrices known in the literature. Next, using the Monte Carlo methods, we show that the entanglement entropy at the interface is higher than in the bulk on the either side, which is expected if some quasiparticles are not able to cross through the interface. This is indeed the case * we find that although all quasiholes remain well-localized when crossing the interface, the statistics of some of them become ill-defined in such a process. Although our work is partly numerical, the closed-form expressions for the wavefunctions allow us to study systems too large for exact diagonalization.

[1] B. Jaworowski, A. E. B. Nielsen, Model wavefunctions for interfaces between lattice Laughlin states, submitted to Physical Review B