Small hole pocket in the Fermi surface of underdoped YBCO

A team of researchers from Université de Sherbrooke, Laboratoire National des Champs Magnétiques Intenses (LNCMI), University of British Columbia, Canadian Institute for Advanced Research and the National High Magnetic Field Laboratory discovered a previously unobserved portion of the Fermi surface in underdoped YBCO. This discovery provides further evidence to support the picture of the Fermi surface being reconstructed as a result of charge density wave order developing in underdoped YBCO prior to the material entering the superconducting state at lower temperatures.