Vortices in quantum spin systems

Hideki Ono, Hiroshi Kuratsuji

Robert J. Kares

John Schliemann, Franz G. Mertens

We examine spin vortices in ferromagnetic quantum Heisenberg models with planar anisotropy on two-dimensional lattices. The symmetry properties and the time evolution of vortices built up from spin-coherent states are studied in detail. Although these states show a dispersion typical for wave packets, important features of classical vortices are conserved. Moreover, the results on symmetry properties provide a construction scheme for vortex-like excitations from exact eigenstates, which have a well-controlled time evolution. Our approach works for arbitrary spin length both on triangular and square lattices.

Л. П. Рапопорт, A.G. Krylovetskii

Richard J. Creswick, Harry L. Morrison

George Vahala, Min Soe, Linda L. Vahala

Using the qubit unitary algorithm developed in the previous paper, quantum reconnection of non-Abelian quantum vortices is simulated and rung-like vortices are seen during the reconnection. Vortices in two of the four tetrahedral symmetry group are examined. Moreover, the algorithm performs exceptionally on classical supercomputers, as shown on timings on the IBM-Q supercomputer MIRA. It is expected that one should see the exponential speedup on a quantum computer since quantum entanglement is crucial for the qubit algorithm to recover the Gross-Pitaevskii equations for spin-2 systems.Keywords : spin-2 BECs, non-Abeliam vortices