FisMat2017 - Submission - View

Abstract's title: Majorana Quasi-Particles Protected by $\mathbb{Z}_2$ Angular Momentum Conservation
Submitting author: Marcello Dalmonte
Affiliation: ICTP, Trieste
Affiliation Address: strada Costiera 11, Trieste
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: \author{F. Iemini} \address{Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, Trieste, Italy} \author{L. Mazza} \address{Departement de Physique, Ecole Normale Superieure / PSL Research University, CNRS, 24 rue Lhomond, F-75005 Paris, France} \author{L. Fallani} \address{Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Italy} \address{LENS European Laboratory for Nonlinear Spectroscopy, I-50019 Sesto Fiorentino, Italy} \author{P. Zoller} \address{Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria} \address{Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria} \author{R. Fazio} \address{Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, Trieste, Italy} \address{NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56126 Pisa, Italy}

We show how angular momentum conservation can stabilise a symmetry-protected quasi-topological phase of matter supporting Majorana quasi-particles as edge modes in one-dimensional cold atom gases. We investigate a number-conserving four-species Hubbard model in the presence of spin-orbit coupling. The latter reduces the global spin symmetry to an angular momentum parity symmetry, which provides an extremely robust protection mechanism that does not rely on any coupling to additional reservoirs. The emergence of Majorana edge modes is elucidated using field theory techniques, and corroborated by density-matrix-renormalization-group simulations. Our results pave the way toward the observation of Majorana edge modes with alkaline-earth-like fermions in optical lattices, where all basic ingredients for our recipe - spin-orbit coupling and strong inter-orbital interactions - have been experimentally realized over the last two years.