Quantum Magnetism with four component fermions

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Quantum Magnetism with four component fermions
2017. 03. 03. 10:15
BME Fizikai Intézet, Elméleti Fizika Tanszék, Budafoki út 8. F-épület, III lépcsőház, szemináriumi szoba
Gergely Szirmai (Wigner Res. Inst.)

We investigate magnetic properties of strongly interacting four component spin-3/2 ultracold fermionic atoms in the Mott insulator limit with one particle per site in an optical lattice. In this limit, atomic tunneling is virtual, and only the atomic spins can exchange. We find a competition between symmetry-breaking and liquidlike disordered phases. Particularly interesting are valence bond states with bond centered magnetizations, situated between the ferromagnetic and conventional valence bond phases. In the framework of a mean-field theory, we calculate the phase diagram and identify an experimentally relevant parameter region where a homogeneous SU(4) symmetric Affleck-Kennedy-Lieb-Tasaki–like valence bond state is present.