Weak antilocalization, spin–orbit interaction, and phase coherence length of a Dirac semimetal Bi0.97Sb0.03

Abstract

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 $$\rho_{xx} \left( B \right)$$ ρ xx B and Hall resistivity $$\rho_{xy} \left( B \right)$$ ρ xy B over a wide temperature (T) range. Compared to the previous approach Vu et al. (Phys Rev B 100:125162, 2019), which assumes infinite phase coherence length (lϕ) and a zero spin–orbit scattering length (lSO), the present framework is more general, covering high T and the intermediate spin–orbit coupling strength. Based on the new approach, the $$\rho_{xx} \left( B \right)$$ ρ xx B and $$\rho_{xy} \left( B \right)$$ ρ xy B of the Dirac semimetal Bi0.97Sb0.03 was analyzed over a wide T range from 1.7 to 300 K. The present framework not only explains the main features of the experimental data but also enables one to estimate lϕ and lSO at different temperatures. The lϕ has a power-law T dependence at high T and saturates at low T. In contrast, the lSO shows negligible T dependence. Because of the different T dependence, a crossover occurs from the lSO-dominant low-T to the lϕ-dominant high-T regions. Accordingly, the hallmark features of weak antilocalization (WAL) in $$\rho_{xx} \left( B \right)$$ ρ xx B and $$\rho_{xy} \left( B \right)$$ ρ xy B are gradually suppressed across the crossover with increasing T. The present theory describes both low-T and high-T regions successfully, which is impossible in the previous approximate approach. This work offers insights for understanding quantum electrical transport phenomena and their underlying physics, particularly when multiple WAL length scales are competing.

Influence of magnetic (Fe) and non-magnetic (In) doping on structural, magnetic, and weak anti-localization properties of Bi2Te3 topological insulator

“…From figure 4(a), it is observed that, the MR% varies linearly with applied magnetic field producing a v-type shape around low field for un-doped Bi 2 Te 3 . This v-type cusp at low field is a signature of quantum features named as weak anti-localization (WAL) effect [5][6][7][8][9][10][11][12][13][14][15]. Because of intrinsic spin-orbit interaction (SOI) in host Bi 2 Te 3 , two self-interacting time-reversal paths of electrons destructively quantum interfere.…”

“…Topological state of quantum materials (QMs) is one of the latest inventions of twenty-first century in condensed matter physics [1][2][3][4][5][6][7][8][9]. Topological insulator (TI) possesses an unconventional identity as there exists both insulating and metallic nature in the same material.…”

“…Topological phenomenon is well visualized in 2D limit, as topological protection successively losses its identity with increasing bulk channels. However, the quantum effect can be seen in 3D limit due to the presence of spin-orbit coupling in 3D bulk channels (although quite weak compared to 2D) [5][6][7][8][9][10][11][12][13][14][15]. When this quantum property meets with extrinsic magnetism, the band structure of host is modified due to the breaking of symmetries [16][17][18][19][20][21][22].…”

Unraveling the effect of solvents on the excited state dynamics of C540A by experimental and theoretical study

“…Excited-state intramolecular charge transfer (ICT) has attracted extensive attention for in-depth understanding of the fundamental deactivation processes and key mechanisms in photochemistry and photobiology. 1–5 The ICT processes are sensitive to the intermolecular hydrogen bond interactions between solute and solvent molecules as an important external factor. 6–9…”

“…Excited-state intramolecular charge transfer (ICT) has attracted extensive attention for in-depth understanding of the fundamental deactivation processes and key mechanisms in photochemistry and photobiology. [1][2][3][4][5] The ICT processes are sensitive to the intermolecular hydrogen bond interactions between solute and solvent molecules as an important external factor. [6][7][8][9] To explore the inuence of intermolecular hydrogen bonds on the excited-state dynamics, [10][11][12][13][14][15] the Kamlet-Ta (K-T) solvatochromic parameters (p*, a, b) have been developed to depict the hydrogen bond interaction between solute and solvent molecules and to depict the spectral redshi in the steady-state absorption and uorescence spectroscopy induced by solvents.…”