2019/06/30 by Dizhou Xie, Tian-Shu Deng, Teng Xiao +4
Physics and Astronomy · #Bose–Einstein condensate #Lattice (music) #Momentum (technical analysis) #Physics #Position and momentum space #Quantum #Quantum algorithm #Quantum and electron transport phenomena #Quantum computer #Quantum many-body systems #Quantum mechanics #Quantum simulator #Quantum walk #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.quant-gas
paper · pdf · doi:10.1103/physrevlett.124.050502
published as Phys. Rev. Lett. 124, 050502 (2020) · 6 pages, 4 figures
arxiv created 2020/01/06 · openalex publication_date 2020/02/05 · arxiv updated 2020/02/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report the experimental implementation of discrete-time topological quantum walks of a Bose-Einstein condensate in momentum space. Introducing stroboscopic driving sequences to the generation of a momentum lattice, we show that the dynamics of atoms along the lattice is effectively governed by a periodically driven Su-Schrieffer-Heeger model, which is equivalent to a discrete-time topological quantum walk. We directly measure the underlying topological invariants through time-averaged mean chiral displacements, which are consistent with our experimental observation of topological phase transitions. We then observe interaction-induced localization in the quantum-walk dynamics, where atoms tend to populate a single momentum-lattice site under interactions that are nonlocal in momentum space. Our experiment opens up the avenue of investigating discrete-time topological quantum walks using cold atoms, where the many-body environment and tunable interactions offer exciting new possibilities.