@article { ISI:000530023600007,
title = {d-wave superconductivity and Bogoliubov-Fermi surfaces in Rarita-Schwinger-Weyl semimetals},
journal = {Phys. Rev. B},
volume = {101},
number = {18},
year = {2020},
month = {MAY 4},
pages = {184503},
publisher = {AMER PHYSICAL SOC},
type = {Article},
abstract = {We uncover the properties of complex tensor (d-wave) superconducting order in three-dimensional Rarita-Schwinger-Weyl semimetals that host pseudospin-3/2 fermions at a fourfold linear band-crossing point. Although the general theory of d-wave order was originally developed for materials displaying quadratic band touching, it directly applies to the case of semimetals with linear dispersion, several candidate compounds of which have been discovered experimentally very recently. The spin-3/2 nature of the fermions allows for the formation of spin-2 Cooper pairs which may be described by a complex second-rank tensor order parameter. In the case of linear dispersion, for the chemical potential at the Fermi point and at strong coupling, the energetically preferred superconducting state is the uniaxial nematic state, which preserves time-reversal symmetry and provides a full (anisotropic) gap for quasiparticle excitations. In contrast, at a finite chemical potential, we find that the usual weak-coupling instability is toward the {\textquoteleft}{\textquoteleft}cyclic state,{{\textquoteright}{\textquoteright}} well known from the studies of multicomponent Bose-Einstein condensates, which breaks time-reversal symmetry maximally, has vanishing average value of angular momentum, and features 16 small Bogoliubov-Fermi surfaces. The Rarita-Schwinger-Weyl semimetals provide therefore the first example of weakly coupled, three-dimensional, isotropic d-wave superconductors where the d-wave superconducting phase is uniquely selected by the quartic expansion of the mean-field free energy, and is not afflicted by the accidental degeneracy first noticed by Mermin over 40 years ago. We discuss the appearance and stability of the Bogoliubov-Fermi surfaces in absence of inversion symmetry in the electronic Hamiltonian, as in the case at hand.},
issn = {2469-9950},
doi = {10.1103/PhysRevB.101.184503},
author = {Link, Julia M. and Boettcher, Igor and Herbut, Igor F.}
}
@article {ISI:000483803100006,
title = {Ground state of the three-dimensional BCS d-wave superconductor},
journal = {Phys. Rev. B},
volume = {100},
number = {10},
year = {2019},
month = {SEP 4},
pages = {104503},
publisher = {AMER PHYSICAL SOC},
type = {Article},
abstract = {We determine the mean-field ground state of the three-dimensional rotationally symmetric d-wave (l = 2) superconductor at weak coupling. It is a noninert state, invariant under the symmetry C-2 only, which breaks time-reversal symmetry almost maximally, and features a high but again less-than-maximal average magnetization. The state obtained by minimization of the expanded sixth-order Ginzburg-Landau free energy is found to be an excellent approximation to the true ground state. The coupling to a parasitic s-wave component has only a minuscule quantitative and no qualitative effect on the ground state.},
issn = {2469-9950},
doi = {10.1103/PhysRevB.100.104503},
author = {Herbut, Igor F. and Boettcher, Igor and Mandal, Subrata}
}
@article { ISI:000375331200002,
title = {Emergent Lorentz symmetry near fermionic quantum critical points in two and three dimensions},
journal = {JOURNAL OF HIGH ENERGY PHYSICS},
number = {4},
year = {2016},
month = {APR 5},
issn = {1029-8479},
doi = {10.1007/JHEP04(2016)018},
author = {Roy, Bitan and Juricic, Vladimir and Herbut, Igor F.}
}
@article { ISI:000373760500009,
title = {Half vortex and fractional electrical charge in two dimensions},
journal = {PHYSICAL REVIEW B},
volume = {93},
number = {15},
year = {2016},
month = {APR 11},
issn = {2469-9950},
doi = {10.1103/PhysRevB.93.155415},
author = {Roy, Bitan and Herbut, Igor F.}
}
@article { ISI:000338043100001,
title = {Zero Modes and Global Antiferromagnetism in Strained Graphene},
journal = {PHYSICAL REVIEW X},
volume = {4},
number = {2},
year = {2014},
month = {MAY 30},
issn = {2160-3308},
doi = {10.1103/PhysRevX.4.021042},
author = {Roy, Bitan and Assaad, Fakher F. and Herbut, Igor F.}
}