1. Topological Varma superfluid in optical lattices
- Author
-
Andreas Hemmerich, M. Di Liberto, C. Morais Smith, Sub Cond-Matter Theory, Stat & Comp Phys, and Theoretical Physics
- Subjects
Topological degeneracy ,FOS: Physical sciences ,General Physics and Astronomy ,02 engineering and technology ,Quantum phases ,Topology ,01 natural sciences ,Topological entropy in physics ,Symmetry protected topological order ,Quantum mechanics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,cond-mat.mes-hall ,Topological order ,010306 general physics ,Topological quantum number ,Physics ,Condensed Matter::Quantum Gases ,Optical lattice ,Condensed Matter - Mesoscale and Nanoscale Physics ,Physique ,021001 nanoscience & nanotechnology ,Quantum Gases (cond-mat.quant-gas) ,Topological insulator ,0210 nano-technology ,Condensed Matter - Quantum Gases ,cond-mat.quant-gas - Abstract
Topological states of matter are peculiar quantum phases showing different edge and bulk transport properties connected by the bulk-boundary correspondence. While non-interacting fermionic topological insulators are well established by now and have been classified according to a ten-fold scheme, the possible realisation of topological states for bosons has not been much explored yet. Furthermore, the role of interactions is far from being understood. Here, we show that a topological state of matter exclusively driven by interactions may occur in the p-band of a Lieb optical lattice filled with ultracold bosons. The single-particle spectrum of the system displays a remarkable parabolic band-touching point, with both bands exhibiting non-negative curvature. Although the system is neither topological at the single-particle level, nor for the interacting ground state, on-site interactions induce an anomalous Hall effect for the excitations, carrying a non-zero Chern number. Our work introduces an experimentally realistic strategy for the formation of interaction-driven topological states of bosons., 6+6 pages
- Published
- 2016