Year: 2017
Type: article
Abstract: Topologically non-trivial Hamiltonians with periodic boundary conditions are characterized by strictly quantized invariants. Open questions and fundamental challenges concern their existence, and the possibility of measuring them in systems with open boundary conditions and limited spatial extension. Here, we consider transport in Hofstadter strips, that is, two-dimensional lattices pierced by a uniform magnetic flux which extend over few sites in one of the spatial dimensions. As we show, an atomic wave packet exhibits a transverse displacement under the action of a weak constant force. After one Bloch oscillation, this displacement approaches the quantized Chern number of the periodic system in the limit of vanishing tunneling along the transverse direction. We further demonstrate that this scheme is able to map out the Chern number of ground and excited bands, and we investigate the robustness of the method in presence of both disorder and harmonic trapping. Our results prove that topological invariants can be measured in Hofstadter strips with open boundary conditions and as few as three sites along one direction.
Source: SciPost Physics
Authors: Samuel Mugel, Alexandre Dauphin, Pietro Massignan, Leticia Tarruell, Maciej Lewenstein, Carlos Lobo, Alessio Celi
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Funders: Fundación Cellex, Centres de Recerca de Catalunya, Institut de Ciències Fotòniques, University of Southampton, Deutsche Forschungsgemeinschaft, Generalitat de Catalunya, Ministerio de Economía y Competitividad, Horizon 2020 Framework Programme, European Research Council, H2020 Future and Emerging Technologies, FP7 Information and Communication Technologies
Awards: G1124226719, G1511318563, G177484282, G1874999417, G2468274194, G2787289165, G3329847252, G3674809337, G3883453253, G4309660370, G4373719529, G4760961572, G5117147876, G5707651282, G600218615, G604991995, G6299623549, G6566983723, Quantum simulations of insulators and conductors, G745058283, G7736198526, G8657455129, G8765763762
OpenAlex ID: W2613999480