Observation of higher-order topological bound states in the continuum using ultracold atoms

Hongru Wang; Hang Li; Zhaoli Dong; Yichen Pan; Wei Yi; Bo Yan

doi:10.59717/j.tip.2026.100015

The Innovation Physics > 2026 Vol. 1 > No. 1 > 100015

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Observation of higher-order topological bound states in the continuum using ultracold atoms

1.
Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, and State Key Laboratory for Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou 310027, China
2.
State Key Laboratory of Precision Spectroscopy, Institute of Quantum Science and Precision Measurement, East China Normal University, Shanghai 200062, China
3.
Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
4.
CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei 230026, China
5.
College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
6.
These authors contributed equally

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Corresponding authors: hli@mail.ecnu.edu.cn (H.L.); wyiz@ustc.edu.cn (W.Y.); yanbohang@zju.edu.cn (B.Y.)
Received Date: May 02, 2026

Accepted Date: September 08, 2026

Published Online: September 17, 2026

The Innovation Physics 1(1), https://doi.org/10.59717/j.tip.2026.100015 | Cite this article

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PUBLIC SUMMARY

PUBLIC SUMMARY
1. A two-dimensional momentum lattice is engineered using ultracold atoms.
  
  Corner and edge bound-state dynamics reveal higher-order topology.
  
  The corner state is identified as a higher-order topological bound state in the continuum.
  
  Adiabatic preparation and topological transition are probed in a programmable cold-atom platform.

ABSTRACT

ABSTRACT

Simulating higher-order topological materials in synthetic quantum matter is an active research frontier for its theoretical significance in fundamental physics and promising applications in quantum technologies. Here we experimentally implement two-dimensional (2D) momentum lattices with highly programmable ability using ultracold ⁸⁷Rb atoms. Through precise control of experimental parameters, we simulate a 2D Su-Schrieffer-Heeger model with this technique, and observe the characteristic dynamics of corner and edge-bound states, where the corner state is identified as a higher-order topological bound state in the continuum. We further study the adiabatic preparation of the corner state by engineering evolutions with time-dependent Hamiltonians. We also demonstrate the higher-order topological phase transition by measuring both the bulk topological invariant and the topological corner state. Our new platform opens the avenue for exploring the exotic dynamics and topology in higher synthetic dimensions, making use of the rich degrees of freedom of cold atoms systems.
- Bose-Einstein Condensate /
- Bound States in the Continuum /
- High-Order Topological phase transition

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Wang H., Li H, Dong Z., et al. (2026). Observation of higher-order topological bound states in the continuum using ultracold atoms. The Innovation Physics 1:100015. https://doi.org/10.59717/j.tip.2026.100015

Wang H., Li H, Dong Z., et al. (2026). Observation of higher-order topological bound states in the continuum using ultracold atoms. The Innovation Physics 1:100015. https://doi.org/10.59717/j.tip.2026.100015

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Observation of higher-order topological bound states in the continuum using ultracold atoms

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