Quantum oscillations in the underdoped cuprate

Quantum oscillations occur via Landau quantisation of the quasiparticle in a Fermi liquid at low temperature. In the light of currently popular notions their detection in the ortho-II-YBa2Cu3O6.45 and YBa2Cu4O8 crystals is inconsistent with this. We explain this in terms of multichannel Kondo model of the underdoped cuprate.