Emerging weak antilocalization effect in Ta_(0.7)Nb_(0.3)Sb_(2)semimetal single crystals  

作　　者：Meng Xu Lei Guo Lei Chen Ying Zhang Shuang-Shuang Li Weiyao Zhao Xiaolin Wang Shuai Dong Ren-Kui Zheng 

机构地区：[1]College of Science,Hohai University,Nanjing 210098,China [2]School of Physics,Southeast University,Nanjing 211189,China [3]School of Physics and Materials Science,Guangzhou University,Guangzhou 510006,China [4]School of Materials Science and Engineering,Jiangxi Engineering Laboratory for Advanced Functional Thin Films,Nanchang University,Nanchang 330031,China [5]Department of Materials Science&Engineering,Monash University,Clayton 3800 VIC,Australia [6]Institute for Superconducting and Electronic Materials,&ARC Centre of Excellence in Future Low-Energy Electronics Technologies,Innovation Campus,University of Wollongong,North Wollongong NSW 2500,Australia

出　　处：《Frontiers of physics》2023年第1期123-132,共10页物理学前沿（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.11974155 and 12104128);the Natural Science Foundation of Jiangsu Province(Grant No.BK20210360);the Postdoctoral Research Program of Jiangsu Province(Grant No.2021K581C);the Fundamental Research Funds for the Central Universities(Grant No.B210201026);W.Z.and X.W.acknowledge the support from ARC Centre of Excellence in Future Low-Energy Electronic Technologies(No.CE170100039).

摘　　要：Weak antilocalization(WAL)effect is commonly observed in low-dimensional systems,three-dimensional(3D)topological insulators and semimetals.Here,we report the growth of high-quality Ta_(0.7)Nb_(0.3)Sb_(2)single crystals via the chemical vapor transport(CVT).Clear sign of the WAL effect is observed below 50 K,probably due to the strong spin–orbital coupling in 3D bulk.In addition,it is worth noting that a relatively large MR of 120%appears under 1 T magnetic field at T=2 K.Hall measurements and two-band model fitting results reveal high carrier mobility(>1000 cm^(2)·V^(–1)·s^(–1)in 2–300 K region),and off-compensation electron/hole ratio of~8:1.Due to the angular dependence of the WAL effect and the fermiology of the Ta_(0.7)Nb_(0.3)Sb_(2)crystals,interesting magnetic-field-induced changes of the symmetry of the anisotropic magnetoresistance(MR)from two-fold(≤0.6 T)to four-fold(0.8–1.5 T)and finally to two-fold(≥2 T)are observed.This phenomenon is attributed to the mechanism shift from the low-field WAL dominated MR to WAL and fermiology co-dominated MR and finally to high-field fermiology dominated MR.All these signs indicate that Ta_(0.7)Nb_(0.3)Sb_(2)may be a topological semimetal candidate,and these magnetotransport properties may attract more theoretical and experimental exploration of the(Ta,Nb)Sb_(2)family.

关 键 词：topological semimetal MAGNETORESISTANCE weak antilocalization effect spin-orbital coupling 

分 类 号：O469[理学—凝聚态物理]