weak antilocalization and phase coherence

Weak antilocalization and phase coherence code#
Weak antilocalization and phase coherence free#

( f) The direct fitting of SdH oscillations from the MR data to the Lifshits-Kosevich formula. The electron interference can be significantly modified if spin. ( e) A Landau fan diagram is constructed from the maximum and minimum of the SdH oscillations. This so- called weak localization effect can even be observed in macroscopic structures. ( d) The amplitude of SdH oscillation versus the inverse magnetic field is plotted to estimate the Dingle equation. A comparison is made between these amplitudes and the Lifshitz-Kosevich equation. ( c) The amplitudes of the SdH oscillations are shown as a function of temperature. Inset of ( b) shows FFT of the SdH oscillations in Δ ρ xy B at T = 1.7 K. Information on phase-coherence can be obtained by analyzing transport phenomena such as weak (anti)localization and universal conductance fluctuations in structures of the according length scale 24. ( b) Fast Fourier transform (FFT) of the SdH oscillations in Δ ρ xx B at different temperatures shows a single oscillation frequency. Insets of ( a) show the SdH oscillations in the Hall resistivity of a Bi 0.97Sb 0.03 single crystal at T = 1.7 K. ( a) Shubnikov-de Haas (SdH) oscillations in the transverse magnetoresistance of a Bi 0.97Sb 0.03 single crystal at different temperatures. This work offers insights for understanding quantum electrical transport phenomena and their underlying physics, particularly when multiple WAL length scales are competing. The phase coherence length is determined by inelastic. The present theory describes both low-T and high-T regions successfully, which is impossible in the previous approximate approach. Weak antilocalization is a transport phenomenon in the quantum diffusion regime in disordered metals. Weak antilocalization signatures observed at low temperatures provided information on spin-orbit scattering length ranging from 20 to 30 nm, elastic scattering length of approx. Accordingly, the hallmark features of weak antilocalization (WAL) in and are gradually suppressed across the crossover with increasing T. Because of the different T dependence, a crossover occurs from the l SO-dominant low-T to the l ϕ-dominant high-T regions. In contrast, the l SO shows negligible T dependence. The l ϕ has a power-law T dependence at high T and saturates at low T. The present framework not only explains the main features of the experimental data but also enables one to estimate l ϕ and l SO at different temperatures. Based on the new approach, the and of the Dirac semimetal Bi 0.97Sb 0.03 was analyzed over a wide T range from 1.7 to 300 K. (Phys Rev B 100:125162, 2019), which assumes infinite phase coherence length (l ϕ) and a zero spin-orbit scattering length (l SO), the present framework is more general, covering high T and the intermediate spin-orbit coupling strength. Compared to the previous approach Vu et al. These results pave the way toward silicon-compatible spintronic devices.The present study develops a general framework for weak antilocalization (WAL) in a three-dimensional (3D) system, which can be applied for a consistent description of longitudinal resistivity and Hall resistivity over a wide temperature (T) range. 2019), which assumes infinite phase coherence length (l) and a zero spinorbit.

Weak antilocalization and phase coherence code#

We also report here the numerical methods and code developed for calculating the magneto-resistance in the ballistic regime, where the commonly used HLN and ILP models for analyzing weak localization and anti-localization are not valid. The present study develops a general framework for weak antilocalization (WAL) in a three-dimensional.

Weak antilocalization and phase coherence free#

As the density becomes larger than ∼6 × 10 11 cm −2, the spin precession length becomes shorter than the mean free path, and the system enters the ballistic spin transport regime. The mobility and the mean free path increase with increasing hole density, while the spin precession length decreases due to increasingly stronger spin–orbit coupling. From the magneto-resistance, we extract the phase-coherence time, spin–orbit precession time, spin–orbit energy splitting, and cubic Rashba coefficient over a wide density range. In this letter, we report the observation of a gate-induced crossover from weak localization to weak anti-localization in the magneto-resistance of a high-mobility two-dimensional hole gas in a strained germanium quantum well. For practical spin field-effect transistors, another essential requirement is ballistic spin transport, where the spin precession length is shorter than the mean free path such that the gate-controlled spin precession is not randomized by disorder. This article gives a clear sign of WAL at low elds and non-saturating linear magneto-resistance (LMR) at higher elds. Gate-controllable spin–orbit coupling is often one requisite for spintronic devices. Coming to the phase coherence dependence on temperature, the de-phasing mechanism in Bi 0.95 Sb 0.05 single crystal is found to be governed by both electron-electron scattering and electron-phonon scattering.