Intertwined orders of cold atoms in a triangular optical lattice

21 November 2023

Photo: AG Hemmerich

Understanding the intricate properties of materials such as high-temperature superconductors and other strongly correlated systems has long been a challenge for scientists. In an international research team with scientists from the Southern University of Science and Technology in Shenzhen, the Chinese Academy of Sciences in Beijing, and the Westlake University in Hangzhou, an unconventional state of matter was generated by arranging rubidium atoms in the second Bloch-band of a triangular optical lattice.

Our experiments confirm the formation of condensates at finite momenta, interaction-induced spontaneous breaking of rotational and time-reversal symmetry, in combination with intertwined exotic stripe and loop current orders, i.e., traits shared with high-temperature superconductors and other advanced quantum materials. The image shows experimentally observed momentum distributions of the three quantum stripe phases associated with the three degenerate symmetry broken ground states.

Evidence for Quantum Stripe Ordering in a Triangular Optical Lattice
X.-Q. Wang, G.-Q. Luo, J.-Y. Liu, G.-H. Huang, Z.-X. Li, C. Wu, A. Hemmerich, and Z.-F. Xu
Phys. Rev. Lett. 131, 226001 (2023).