![]() ![]() The extremely large magnetoresistance and high mobility of topological insulators have great technological value and can be exploited in magnetoelectric sensors and memory devices. The effect manifests itself as a positive. The WL effect is revealed by an increase in resistivity at low temperatures and by a peculiar MR behavior related to the phase shift induced by the magnetic field. At high charge-carrier concentrations, there is a greater number of conduction channels and a decrease in the phase coherence length compared to low charge-carrier concentrations. Weak localization is a physical effect which occurs in disordered electronic systems at very low temperatures. The physical parameters characterizing the WAL effects are calculated using the Hikami-Larkin-Nagaoka formula. The observations of an extremely large nonsaturating magnetoresistance and ultrahigh mobility in the samples with lower carrier density further support the presence of surface states. The measured WAL effect follows the Hikami-Larkin-Nagaoka (HLN) model and the extracted values of phase coherence length (l) and are 420 nm and 0.52 respectively. WAL due to topological surface states shows no dependence on the nature (electrons or holes) of the bulk charge carriers. At high charge-carrier density the WAL curves scale with neither the applied field nor its normal component, implying a mixture of bulk and surface conduction. The key parameters or length scales to determine the strength of weak localization or anti-localization are phase coherence length and SOI induced spin. At low charge-carrier density the WAL curves scale with the normal component of the magnetic field, demonstrating the dominance of topological surface states in magnetoconductivity. At high charge-carrier concentrations, there is a greater number of conduction channels and a decrease in the phase coherence length compared to low charge-carrier concentrations. Systematic comparison of the transport properties of single-valley Weylįermions, 2D massless Dirac fermions, and 3D conventional electrons.Weak antilocalization (WAL) effects in Bi 2 Te 3 single crystals have been investigated at high and low bulk charge-carrier concentrations. Weak antilocalization (WAL) effects in Bi 2 Te 3 single crystals have been investigated at high and low bulk charge-carrier concentrations. Temperatures and leads to a tendency to localization. Interaction and disorder scattering always dominates the conductivity at low The measured weak anti-localization effect agrees well with the Hikami-Larkin-Nagaoka model and the extracted phase coherent length shows a power-law dependence with temperature ( T 0.44. When B depends 0, qi on the is proportional phase to coherence. In addition, we find that the interplay of electron-electron The weak antilocalization has been widely observed in three-dimensional Dirac and. In the presence of strong intervalley scattering andĬorrelations, we expect a crossover from the weak antilocalization to weak ![]() Magnetoconductivity near zero field, thus gives one of the transport signaturesįor Weyl semimetals. Evidence of separation of transport channels in Hall data is seen, with a parallel conductivity contribution from bulk states. For a mesoscopic system with disorder and strong spin-orbit coupling, the phase coherent magneto-transport at low temperatures result in the appearance of weak antilocalization (WAL) and universal conductance fluctuations (UCF) effects. The weak antilocalization always dominates the The characteristic weak antilocalization (WAL) signature of the topological surface states is seen in the magnetoresistance (MR), which acts in combination with EEI effects at low-temperatures and low-fields. Including the contributions from the weak antilocalization, Berry curvatureĬorrection, and Lorentz force, we compare the calculated magnetoconductivity 1 The name emphasizes the fact that weak localization is a precursor of Anderson localization, which occurs at strong disorder. Awana1,2 1CSIR -National Physical Laboratory, Dr. The effect manifests itself as a positive correction to the resistivity of a metal or semiconductor. 1 Surface states induced weak anti-localization effect in Bi 0.85 Sb 0.15 topological single crystal Yogesh Kumar1,2 and V.P.S. Magnetoconductivity is negative and proportional to the square root of magneticįield at low temperatures, as a result of the weak antilocalization. Weak localization is a physical effect which occurs in disordered electronic systems at very low temperatures. For a single valley of Weyl fermions, we find that the Weak localization and weak anti-localization are quantum interference effects in quantum transport in a disordered electron system. Download a PDF of the paper titled Weak antilocalization and localization in disordered and interacting Weyl semimetals, by Hai-Zhou Lu and Shun-Qing Shen Download PDF Abstract: Using the Feynman diagram techniques, we derive the finite-temperatureĬonductivity and magnetoconductivity formulas from the quantum interference andĮlectron-electron interaction, for a three-dimensional disordered Weyl ![]()
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