Lifshitz transition in underdoped cuprates

Recent studies show that quantum oscillations thought to be associated with a density wave reconstructed Fermi surface disappear at a critical value of the doping for YBa(2)Cu(3)O(6+y) and the cyclotron mass diverges as the critical value is approached from the high doping side. We argue that the phenomenon is due to a Lifshitz transition where the pockets giving rise to the quantum oscillations connect to form an open (quasi-one-dimensional) Fermi surface. The estimated critical doping is close to that found by experiment and the theory predicts a logarithmic divergence of the cyclotron mass with a coefficient comparable to that observed in experiment.