Magnetization-governed magnetoresistance anisotropy in the topological semimetal CeBi

Abstract

Magnetic topological semimetals, the latest member of topological quantum materials, are attracting extensive attention as they may lead to topologically-driven spintronics. Currently, magnetotransport investigations on these materials are focused on the anomalous Hall effect. Here, we report on the magnetoresistance anisotropy of topological semimetal CeBi, which has tunable magnetic structures arising from localized Ce 4f electrons and exhibits both negative and positive magnetoresistances, depending on the temperature. We found that the angle dependence of the negative magnetoresistance, regardless of its large variation with the magnitude of the magnetic field and with temperature, is solely dictated by the field-induced magnetization that is orientated along a primary crystalline axis and flops under the influence of a rotating magnetic field. The results reveal the strong interaction between conduction electrons and magnetization in CeBi. They also indicate that magnetoresistance anisotropy can be used to uncover the magnetic behavior and the correlation between transport phenomena and magnetism in magnetic topological semimetals.Stimulated by the fascinating properties discovered in topological insulators [1], topological quantum materials have become an exciting frontier in condensed matter physics and materials science [2][3][4][5][6][7][8]. Among them, magnetic topological insulators with strong correlations between magnetism and nontrivial band topology exhibit exotic phenomena such as quantum anomalous Hall effect [5,[8][9][10][11] and axion insulator state [12]. However, those novel properties were observed in thin films of magnetic topological insulators converted from known topological insulators by doping magnetic atoms, e.g., chromium-doped (Bi,Sb)2Te3 [10,11] or in a ferromagnet-topological insulator-ferromagnet (FM-TI-FM) sandwich heterostructure [12]. Their fabrication requires advanced molecular beam epitaxy techniques [10][11][12]. The random magnetic dopants also inevitably introduce disorder that can hinder further exploration of topological quantum effects in the material [13,14]. Thus, topological insulators with intrinsic magnetic ordering have been

Synthesis and characterization of single crystals of rare-earth containing magnetic topological semimetal candidates

“…shows the Kohler's plot obtained from the resistance R(T ) measured at various fields above 5 T, in the temperature range 1.8 K≤ T ≤ 10 K. The anisotropic MR behavior of CeBi was studied recently Lyu et al (2019), and it suggests a magnetization governed MR in the temperature regime ∼ 12.8 K -25 K. This is not inconsistent with our results. Whereas, they observe a magnetization dependent magnetoresistance in the temperature regime between T N /2 < T < T N , we focus on the Kohler's rule behavior below that and the shift to negative MR above that temperature region.…”

“…The relaxation technique is usually used for measurements below 100 K, as the relaxation times are smaller in that temperature range. CeBi, the heaviest member of the CeX family, is known to show multiple metamagnetic transitions in the magnetic field -temperature phase space, with a strong anisotropy arising from crystalline electric field (CEF) effects and a resultant anisotropic magnetoresistance Bartholin et al (1974Bartholin et al ( , 1979; Rossat-Mignod et al (1980; Kohgi et al (2000); Lyu et al (2019). It thus provides an exemplary candidate to study the effects of magnetic ordering in magnetoresistance and electronic structure.…”

Anisotropic magnetoresistance and electronic features of the candidate topological compound praseodymium monobismuthide

“…28,45,59,62,63 Interestingly, similar angular magnetoresistance occurs in ErBi owing to its weak anisotropic magnetization. 28 However, different cases emerge in the sister compounds with strong magnetic anisotropy, such as CeSb, 10 CeBi 64 and HoSb. 58 It is reported that their extra magnetoresistance minima in CeSb and CeBi occur when Ce Γ (1) 8 orbital flops 10,64 and extra magnetoresistance minima in HoSb appear when it undergoes a phase transition from ferromagnetic to HoP-type antiferromagnetic state and vice versa .…”

“…28 However, different cases emerge in the sister compounds with strong magnetic anisotropy, such as CeSb, 10 CeBi 64 and HoSb. 58 It is reported that their extra magnetoresistance minima in CeSb and CeBi occur when Ce Γ (1) 8 orbital flops 10,64 and extra magnetoresistance minima in HoSb appear when it undergoes a phase transition from ferromagnetic to HoP-type antiferromagnetic state and vice versa . 58 Here, except for the ones at ∼ n π/2, no other obvious magnetoresistance minima can be observed in PrBi.…”