Scientific Achievement

  • Researchers in the Van der Waals program identified experimental realization of a thermodynamically stable exciton crystal, i.e. a bosonic analogue to a Wigner lattice

Significance and Impact

  • Established moiré electron-hole bilayers as a versatile platform for realizing correlated crystalline phases of bosons, complementary to ultracold atoms

Research Details

  • Studied the behavior of long-lived interlayer excitons in a moiré potential
  • At 1/3 exciton filling, optical spectroscopy showed an Umklapp peak and a resistance peak in exciton transport confirming the formation of an exciton crystal
  • Found coexistence of excitonic insulators with charge crystals when doped away from charge neutrality

Publication Details

R. Qi, Q. Li, H. Kim, J. Nie, Z. Zhang, R. Xia, Z. Cui, J. Xiao, T. Taniguchi, K. Watanabe, M. F. Crommie, F. Wang, Nature Physics (2026).

DOI: 10.1038/s41567-026-03184-9

Work was performed at Lawrence Berkeley National Lab.