Magnetotransport properties of theα-T₃model

Abstract

Using the well-known Kubo formula, we evaluate magnetotransport quantities, such as the collisional and Hall conductivities of the α-T model. The collisional conductivity exhibits a series of peaks at a strong magnetic field. Each of the conductivity peaks for [Formula: see text] (graphene) splits into two in the presence of a finite α. This splitting occurs due to a finite phase difference between the contributions coming from the two valleys. The density of states is also calculated to explore the origin of the splitting of conductivity peaks. As α approaches 1, the right split part of a conductivity peak comes closer to the left split part of the next conductivity peak. At [Formula: see text], they merge with each other to produce a new series of the conductivity peaks. On the other hand, the Hall conductivity undergoes a smooth transition from [Formula: see text] to [Formula: see text] with n = 0,1,2,... as we tune α from 0-1. For intermediate α, we obtain the Hall plateaus at values 0,2,4,6,8,... in units of e/h.

Unconventional quantum Hall effects in two-dimensional massive spin-1 fermion systems

“…The conductance vanishes when the Fermi surface lies in the first gap of Landau levels (LLs) (the gap between the zero energy and the first nonzero energy levels) despite the existence of an unlimited number of zero energy LLs. For the dice model where there exist a pair of spin-1 points, the Hall conductance takes even numbers, reminiscent of the bilayer grephene 36 . In this paper, we study the QHE in a 2D system with a pair of spin-1 fermions with a mass term m zŜz .…”

Magnetic field independent shape of the zero-energy landau levels in a disordered T3 model

“…The magnetoconductivity σ yy col is given by . The magnetoconductivity of the LLs with s=±1 is calculated by Biswas et al [33]. In their work, the scattering between eigenstates is only allowed with identical Landau indexes n=n′, because of the existence of the term δ(ε ζ −ε ζ′ ) in equation (17).…”

“…Recently, there is a growing interest in studying the T 3 model [23][24][25][26][27][28][29][30][31][32][33]. Experimentally, the lattice can be realized in a trilayer structure of the face-centered cubic lattice, such as SrTiO 3 /SrIrO 3 /SrTiO 3 heterostructures [34,35].…”

Valley-polarized magnetoconductivity and particle-hole symmetry breaking in a periodically modulated α−T3 lattice

“…[10]. As we are considering a doped α-T 3 lattice where the Fermi level is well inside the conic band, we ignore the effects of the flat band in our analysis.…”

“…Moreover, the continuous evolution of α from 0 (graphene) to 1 (T 3 ) can be linked to a variable Berry phase by suitably parametrizing α 7 . The Berry phase, the geometrical phase arising during an adiabatic cyclic evolution of a quantum state, plays a vital role in explaining different properties of a system 8 such as the dc Hall conductivity 9 , magneto-transport properties in the presence of randomly scattered charged impurities 10 , and optical 4,11,12 properties. Note that, Berry phase is π and 0, respectively in graphene and the T 3 lattice setting the two limits of α-T 3 system.…”