• DOI:10.1038/nphys3622
• Corpus ID: 118033107

Topological Thouless pumping of ultracold fermions

@article{Nakajima2016TopologicalTP,
  title={Topological Thouless pumping of ultracold fermions},
  author={Shuta Nakajima and Takafumi Tomita and Shintaro Taie and Tomohiro Ichinose and Hideki Ozawa and Lei Wang and Matthias Troyer and Yoshiro Takahashi},
  journal={Nature Physics},
  year={2016},
  volume={12},
  pages={296-300}
}

• S. Nakajima, T. Tomita, +5 authors Yoshiro Takahashi
• Published 8 July 2015
• Physics
• Nature Physics

Charge transport in a cyclically time-modulated periodic potential, also known as a topological Thouless pump, has been realized in an ultracold gas of fermionic atoms. An electron gas in a one-dimensional periodic potential can be transported even in the absence of a voltage bias if the potential is slowly and periodically modulated in time. Remarkably, the transferred charge per cycle is sensitive only to the topology of the path in parameter space. Although this so-called Thouless charge pump was first proposed more than thirty years ago1, it has not yet been realized. Here we report the demonstration of topological Thouless pumping using ultracold fermionic atoms in a dynamically controlled optical superlattice. We observe a shift of the atomic cloud as a result of pumping, and extract the topological invariance of the pumping process from this shift. We demonstrate the topological nature of the Thouless pump by varying the topology of the pumping path and verify that the topological pump indeed works in the quantum regime by varying the speed and temperature.