Abstract Synthetic gauge fields in synthetic dimensions are now of great interest. This concept provides a convenient manner for exploring topological phases of matter. Here, we report on the first experimental realization of an atom-optically synthetic gauge field based on the synthetic momentum-state lattice of a Bose gas of 133Cs atoms, where magnetically controlled Feshbach resonance is used to tune the interacting lattice into noninteracting regime. Specifically, we engineer a noninteracting one-dimensional lattice into a two-leg ladder with tunable synthetic gauge fields. We observe the flux-dependent populations of atoms and measure the gauge field-induced chiral currents in the two legs. We also show that an inhomogeneous gauge field could control the atomic transport in the ladder. Our results lay the groundwork for using a clean noninteracting synthetic momentum-state lattice to study the gauge field-induced topological physics.Abstract Synthetic gauge fields in synthetic dimensions are now of great interest. This concept provides a convenient manner for exploring topological phases of matter. Here, we report on the first experimental realization of an atom-optically synthetic gauge field based on the synthetic momentum-state lattice of a Bose gas of 133Cs atoms, where magnetically controlled Feshbach resonance is used to tune the interacting lattice into noninteracting regime. Specifically, we engineer a noninteracting one-dimensional lattice into a two-leg ladder with tunable synthetic gauge fields. We observe the flux-dependent populations of atoms and measure the gauge field-induced chiral currents in the two legs. We also show that an inhomogeneous gauge field could control the atomic transport in the ladder. Our results lay the groundwork for using a clean noninteracting synthetic momentum-state lattice to study the gauge field-induced topological physics.

Light Science & ApplicationsJan 7, 202244 citations

Observation of interaction-induced asymmetric chiral currents in a synthetic zigzag ladder

Hongxing Zhao, Huiying Du, Yunfei Wang +8 more

Engineering artificial gauge fields in synthetic lattices offers an efficient avenue for exploring topological states in cold atomic physics and photonics in recent years. Interactions between the system constituents in synthetic dimensions become long ranged, and can induce more striking features. Here, we report the experimental observation of asymmetric chiral currents induced by interactions in a synthetic zigzag ladder with tunable staggered flux, based on the laser-driven coupling of discrete momentum states of ultracold $^{133}\mathrm{Cs}$ atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.Engineering artificial gauge fields in synthetic lattices offers an efficient avenue for exploring topological states in cold atomic physics and photonics in recent years. Interactions between the system constituents in synthetic dimensions become long ranged, and can induce more striking features. Here, we report the experimental observation of asymmetric chiral currents induced by interactions in a synthetic zigzag ladder with tunable staggered flux, based on the laser-driven coupling of discrete momentum states of ultracold $^{133}\mathrm{Cs}$ atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.

Physical Review AJul 18, 20252 citations

Generation of tunable correlated atoms beams in an optical lattice

Marie Bonneau, Josselin Ruaudel, Raphael Lopes +4 more

Jul 23, 20120 citations

Correlated Dynamics in a Synthetic Lattice of Momentum States

Fangzhao Alex An, Η. Meier, Jackson Ang’ong’a +1 more

We study the influence of atomic interactions on quantum simulations in momentum-space lattices (MSLs), where driven transitions between discrete momentum states mimic transport between sites of a synthetic lattice. Low-energy atomic collisions, which are short ranged in real space, relate to nearly infinite-ranged interactions in momentum space. However, the added exchange energy between atoms in distinguishable momentum states leads to an effectively attractive, finite-ranged interaction between atoms in momentum space. In this Letter, we observe the onset of self-trapping driven by such interactions in a momentum-space double well, paving the way for more complex many-body studies in tailored MSLs. We consider the types of phenomena that may result from these interactions, including the formation of chiral solitons in zigzag flux lattices.We study the influence of atomic interactions on quantum simulations in momentum-space lattices (MSLs), where driven transitions between discrete momentum states mimic transport between sites of a synthetic lattice. Low-energy atomic collisions, which are short ranged in real space, relate to nearly infinite-ranged interactions in momentum space. However, the added exchange energy between atoms in distinguishable momentum states leads to an effectively attractive, finite-ranged interaction between atoms in momentum space. In this Letter, we observe the onset of self-trapping driven by such interactions in a momentum-space double well, paving the way for more complex many-body studies in tailored MSLs. We consider the types of phenomena that may result from these interactions, including the formation of chiral solitons in zigzag flux lattices.

arXiv:1702.07315Physical Review LettersJan 25, 201887 citations

Many-body effects in momentum-space lattices

Fangzhao An, Η. Meier, Bryce Gadway

Bulletin of the American Physical SocietyMay 30, 20190 citations

^{133}\mathrm{Cs}

atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.