TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.17.1.003
TI  - A higher-order topological twist on cold-atom SO($5$) Dirac fields
PY  - 2024/07/04
UR  - https://scipost.org/SciPostPhys.17.1.003
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 17
IS  - 1
SP  - 003
A1  - Bermudez, Alejandro
AU  - González-Cuadra, Daniel
AU  - Hands, Simon
AB  - Ultracold Fermi gases of spin-3/2 atoms provide a clean platform to realise SO($5$) models of 4-Fermi interactions in the laboratory. By confining the atoms in a two-dimensional Raman lattice, we show how this system can be used as a flexible quantum simulator of Dirac quantum field theories (QFTs) that combine Gross-Neveu and Thirring interactions with a higher-order topological twist. We show that the lattice model corresponds to a regularization of this QFT with an anisotropic twisted Wilson mass. This allows us to access higher-order topological states protected by a discrete SO($5$) group, a remnant of the continuous rotational symmetry of the 4-Fermi interactions that is not explicitly broken by the lattice discretization. Using large-$N$ methods, we show that the 4-Fermi interactions lead to a rich phase diagram with various competing fermion condensates. Our work opens a route for the implementation of correlated higher-order topological states with tunable interactions that has interesting connections to non-trivial relativistic QFTs of Dirac fermions in $D=2+1$ dimensions.
ER  -

@Article{10.21468/SciPostPhys.17.1.003,
	title={{A higher-order topological twist on cold-atom SO($5$) Dirac fields}},
	author={Alejandro  Bermudez and Daniel González-Cuadra and  Simon Hands},
	journal={SciPost Phys.},
	volume={17},
	pages={003},
	year={2024},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.17.1.003},
	url={https://scipost.org/10.21468/SciPostPhys.17.1.003},
}