Quantum oscillations in magnetic-field–induced antiferromagnetic phase of underdoped cuprates: Application to ortho-II YBa ₂ Cu ₃ O _6.5

Abstract

The magnetic-field-induced antiferromagnetic phase of the underdoped cuprates is studied within the t-t′-J model. A magnetic field suppresses the pairing amplitude, which, in turn, may induce antiferromagnetism. We apply our theory to interpret the recently reported quantum oscillations in high magnetic field in ortho-II YBa 2Cu 3O 6.5 [1] and propose that the total hole density abstracted from the oscillation period is reduced by 50% due to doubling of the unit cell. © Europhysics Letters Association.