Berry curvature induced magnetotransport in 3D noncentrosymmetric metals

Abstract

We study the magnetoelectric and magnetothermal transport properties of noncentrosymmetric metals using semiclassical Boltzmann transport formalism by incorporating the effects of Berry curvature (BC) and orbital magnetic moment (OMM). These effects impart quadratic-B dependence to the magnetoelectric and magnetothermal conductivities, leading to intriguing phenomena such as planar Hall effect, negative magnetoresistance (MR), planar Nernst effect and negative Seebeck effect. The transport coefficients associated with these effects show the usual oscillatory behavior with respect to the angle between the applied electric field and magnetic field. The bands of noncentrosymmetric metals are split by Rashba spin–orbit coupling except at a band touching point (BTP). For Fermi energy below (above) the BTP, giant (diminished) negative MR is observed. This difference in the nature of MR is related to the magnitudes of the velocities, BC and OMM on the respective Fermi surfaces, where the OMM plays the dominant role. The absolute MR and planar Hall conductivity show a decreasing (increasing) trend with Rashba coupling parameter for Fermi energy below (above) the BTP.

Energy magnetization and transport in systems with a non-zero Berry curvature in a magnetic field

“…The non-equilibrium distribution function, which is calculated in section VI up to leading order in the external potential and temperature gradients for a two-dimensional system, is responsible for the regular Hall and Nernst responses and captures the effects of Berry curvature on these. Similar expressions for the non-equilibrium part of the distribution were obtained in several papers [18,50,51], but only in the context of chiral magnetic effects, which are absent in two dimensions. When the Berry curvature Ω = 0, the non-equilibrium parts of the distributions obtained in the above-mentioned papers only lead to regular Ohmic transport, but not the regular Hall effect.…”

Orbital Hall effect in bilayer transition metal dichalcogenides: From the intra-atomic approximation to the Bloch states orbital magnetic moment approach

“…Later, this intrinsic magnetic moment was connected with Berry phase theory and interpreted in a more transparent picture of the self-rotation of semiclassical wave-packet [66]. The description of OAM operator in terms of the orbital magnetic moment of Bloch states was extensively explored [19,20,[67][68][69][70][71][72], acquiring the support of the modern theory of orbital magnetization [46][47][48][49][50]. Recently, it was proposed in Ref.…”

Direction-dependent conductivity in planar Hall set-ups with tilted Weyl/multi-Weyl semimetals

“…The resulting components of the conductivity tensor, which lie in the êE êB -plane, are commonly known as the longitudinal magnetoconductivity (LMC) and the planar Hall conductivity (PHC). Their behaviour in various experimental set-ups has been extensively investigated in the literature [34,40,[70][71][72][73][74][75][76][77][78]. An untilted WSM is intrinsically isotropic and, hence, it will show the same response irrespective of how we choose to orient the êE and êB unit vectors.…”