A phenomenological model that considers different secondary idxy gap amplitudes and quasiparticle effective charges for each nodal direction, is proposed to explain the observed anisotropic node removal by a magnetic field in high-Tc cuprates. Two independent parity-breaking condensates <Ψiˉ⋀Ψi> develop, implying the induction of a magnetic moment per each nodal direction. The model outcomes are in agreement with the experimentally found relation Δi∼B. The secondary gap vanishes through a second-order phase transition at a critical temperature whose value for underdoped nodal-oriented YBCO is estimated to be ∼6K for a field of 15 T.
@article{arxiv.cond-mat/0309046,
title = {Anisotropic Node Removal in d-wave Superconductors under Magnetic Field},
author = {Efrain J. Ferrer and Vivian de la Incera},
journal= {arXiv preprint arXiv:cond-mat/0309046},
year = {2007}
}