A Thouless quantum pump with ultracold bosonic atoms in an optical superlattice

By M. Lohse, C. Schweizer, Oded Zilberberg, M. Aidelsburger, I. Bloch. Nature Physics, 2015

634 citations recorded by the source corpus.

Topological charge pumping enables the transport of charge through an adiabatic cyclic evolution of the underlying Hamiltonian. In contrast to classical transport, the transported charge is quantized and purely determined by the topology of the pump cycle, making it robust to perturbations. Here, we report on the realization of such a pump with ultracold bosonic atoms forming a Mott insulator in a dynamically controlled optical superlattice. By taking in situ images of the cloud, we observe a quantized deflection per pump cycle. We reveal the pump’s genuine quantum nature by showing that, in contrast to ground-state particles, a counterintuitive reversed deflection occurs for particles in the first excited band. Furthermore, we directly demonstrate that the system undergoes a controlled topological transition in higher bands when tuning the superlattice parameters. These results open a route to the implementation of more complex pumping schemes, including spin degrees of freedom and higher dimensions. Thouless introduced the idea of a topological charge pump: the quantized motion of charge due to the slow cyclic variation of a periodic potential. This topologically protected transport has now been realized with ultracold bosonic atoms.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/bb5f3cff56c42966af507e85f2eb2e4534aa6739

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

Topological bands for ultracold atoms (2018, background): “Lohse, M, C. Schweizer, O. Zilberberg, M. Aidelsburger, and I. Bloch (2016), “A Thouless quantum pump with ultracold bosonic atoms in an optical superlattice,” Nat Phys 12 (4), 350–354.”
Topological Thouless pumping of ultracold fermions (2015, background): “[31] observing the topological Thouless pumping with bosonic atoms in Mott insulator state.”
Roadmap on topological photonics (2022, positive): “As a result, only a few years ago, quantized topological pumping was observed for the first time in more controllable cold atoms experiments [88].”
Symmetry and Topology in Non-Hermitian Physics (2018, background): “[202] M.”
Thouless pumping and topology (2022, background): “For implementations based on cold atoms in bichromatic superlattices [12, 13], the local site-dependent potential can be expressed as ∆m(φ) = −∆ cos(2παm − φ), where α = ds/dl is the ratio of the two lattice constants.”
Topological characterizations of an extended Su–Schrieffer–Heeger model (2019, neutral): “[26] Lohse, M.”
Artificial gauge fields in materials and engineered systems (2017, positive): “These ideas have been successfully realized in photonic systems [175,176,177] and ultracold atoms [178,179,180,181], and recently enabled studies of 4D quantum Hall physics based on 2D topological pumping [182,183].”