• DOI:10.1038/s41377-022-00990-7
• Corpus ID: 252760285

Measuring Zak phase in room-temperature atoms

@article{Mao2021MeasuringZP,
  title={Measuring Zak phase in room-temperature atoms},
  author={Ruosong Mao and Xingqi Xu and Jiefei Wang and Chenran Xu and Gewei Qian and Han Cai and Shi-Yao Zhu and Da-Wei Wang},
  journal={Light, Science \& Applications},
  year={2021},
  volume={11}
}

• Ruosong Mao, Xingqi Xu, +5 authors Da-Wei Wang
• Published 24 November 2021
• Physics
• Light, Science & Applications

Cold atoms provide a flexible platform for synthesizing and characterizing topological matter, where geometric phases play a central role. However, cold atoms are intrinsically prone to thermal noise, which can overwhelm the topological response and hamper promised applications. On the other hand, geometric phases also determine the energy spectra of particles subjected to a static force, based on the polarization relation between Wannier-Stark ladders and geometric Zak phases. By exploiting this relation, we develop a method to extract geometric phases from energy spectra of room-temperature superradiance lattices, which are momentum-space lattices of timed Dicke states. In such momentum-space lattices the thermal motion of atoms, instead of being a source of noise, provides effective forces which lead to spectroscopic signatures of the Zak phases. We measure Zak phases directly from the anti-crossings between Wannier-Stark ladders in the Doppler-broadened absorption spectra of superradiance lattices. Our approach paves the way of measuring topological invariants and developing their applications in room-temperature atoms. Atoms moving through standing-wave lasers accumulate Zak phases, which have spectroscopic signatures, enabling room-temperature geometric phase reconstruction in momentum-space superradiance lattices.