A condensate of excitons was theoretically conjectured in the 1960s but has been challenging to pinpoint experimentally. A recent study coordinated by Massimo Rontani from Cnr Nano and David Cobden from the University of Washington present evidence that the two-dimensional bulk of monolayer tungsten ditelluride, WTe2, contains electrons and holes bound by Coulomb attraction that spontaneously form in thermal equilibrium.
Evidence for equilibrium exciton condensation in monolayer WTe2
Bosong Sun, Wenjin Zhao, Tauno Palomaki, Zaiyao Fei, Elliott Runburg, Paul Malinowski, Xiong Huang, John Cenker, Yong-Tao Cui, Jiun-Haw Chu, Xiaodong Xu, S. Samaneh Ataei, Daniele Varsano, Maurizia Palummo, Elisa Molinari, Massimo Rontani & David H. Cobden
Nature Physics 18, pages 94–99 (2022)