Unconventional Hall Effect in Pnictides from Interband Interactions

Abstract

We calculate the Hall transport in a multiband system with a dominant interband interaction between carriers having electron and hole character. We show that this situation gives rise to an unconventional scenario, beyond the Boltzmann theory, where the quasiparticle currents dressed by vertex corrections acquire the character of the majority carriers. This leads to a larger (positive or negative) Hall coefficient than what may be expected on the basis of the carrier balance, with a marked temperature dependence. Our results explain the puzzling measurements in pnictides and provide a more general framework for transport properties in multiband materials.

On the possibility of fast vortices in the cuprates: A vortex plasma model analysis of THz conductivity and diamagnetism in La2−xSrxBilbro1, Aguilar2, Логвенов3 et al. 2011Phys. Rev. B215190View full textAdd to dashboardCite

“…Note that the magnetic susceptibility appears to become singular as B → 0 near T c ("fragile London rigidity") [6], so that evaluating D at lower fields (corresponding to our B = 0 TTDS experiment) will only increase the ratio of χ/G and the discrepancy with the BS estimate. Although there is an expectation that due to their d-wave nature, short coherence lengths, gapped vortex core, and proximity to the Mott insulator, the cuprate vortices may be "fast" as compared to the BS estimate [26][27][28][29][30][31][32], the discrepancy we find is extreme. It is an open question whether a diffusion constant as large as we have found can be reconciled.…”

“…Although detailed calculations must be performed, it is possible that such anomalously fast diffusion may arise as a consequence of the cuprates' d-wave nature and small gapped cores [31,33], inhomogeneities [34], the existence of a competing state nucleated in the vicinity of a vortex [28], or the proximity to a Mott insulator [30,32]. Alternatively, if calculations show that vortex dissipation must always be at least parametrically related to the BS estimate by numbers of order unity, then our analysis shows that there must be another large contribution to the diamagnetic response that is not superconducting in origin (See Ref.…”

Transport in multiband systems with hot spots on the Fermi surface: Forward-scattering corrections

“…With the Curie-Weiß temperature −θ CW < 0, the frequency scale and the correlation length are given by 14,22 The transport is governed by states on the Fermi pockets, denoted by |s, θ , where s = h, e1, e2 is the pocket index and θ is the polar angle along the pocket, see Fig. 1.…”

Flow equation approach to the linear response theory of superconductors

“…Our study can be regarded as complementary to the recent Quantum Monte Carlo (QMC) simulations for the same cooperon-fermion model [22]. It has also some resemblance to considerations of the superconducting fluctuations beyond the gaussian approximation carried out in the t-J model [23].…”