Supplementary Material to

Weak Antilocalization Effectand NocentrosymmetricSuperconductivity in a Topologically Nontrivial Semimetal LuPdBi

Guizhou Xu1, Wenhong Wang1, Xiaoming Zhang1, Yin Du1, Enke Liu1, Shouguo Wang1, Guangheng Wu1,Zhongyuan Liu2, and Xi Xiang Zhang3

1 State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004, P. R. China

3 Division of Physical Science and Engineering, Core Labs, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia

  1. Universal conductance fluctuations under high magnetic fields

Figures S1(a-b) show the raw MR data at 10K and the magnetocondutance variation G at various temperatures in the field range of 4-9T. Although no fixed period can be identified in the fluctuation, the gradual decreasing of the amplitude of G with increasing temperature distinguishes it from a random noise signal. Arising from the quantum interference effect of different scattering paths, UCF takes place in the phase-coherent region featured with a reproducible aperiod structure, in which the amplitudes change in the order of [1]. As discussed in [2], this quantum interference probably belongs to a new category but still relates to the topological surface states by hybridization with the bulk bands around the Fermi level. We find that the scaling of root-mean-square (rms) of G with temperature follows a power law of T-0.6 (Figure S1(c)). According to the UCF theory, when the sample length is larger than L and thermal length LT, the Grms vs T should follow the relation of GrmsT(d-4)/4, d is the dimension [3]. Hence, the conductance fluctuations we detected possess a two-dimensional nature, reflecting the contribution of surface states transport.

Figure S1 (color online) (a) the longitudinal Rxx from -10T to 10T at a temperature of 10K; (b) G plotted in the field from 4 to 9 T at different temperatures;(c) temperature dependence of rmsG and a power law fitted to it (red line).

  1. Comparison of magnetoresistance in LaPdBi and LuPdBi.

Figure S2 shows the magnetoresistance of LaPdBi and LuPdBi, both in perpendicular fields. It can be seen that the MR of LaPdBi belongs to the classical regime with a standard multiband model [4,5] fitted in the whole field range. On the other hand, YPdBi given in [6] reveals a large and quantum linear MR. Unlike either of them, the high field MR of LuPdBi is classical with a simple parabolic relationship, while the low field MR deepens sharply, which is probably caused by the weak antilocalization effect, a signature of surface state transport, as outlined in the main text.

Figure S2.Magnetoresistance of (a)LaPdBi at 10K and (b) LuPdBi at 2K, respectively. The red line represents the fit using a multiband standard model () and a simple parabolic model (), respectively.

References

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[3]J. Checkelsky, Y. Hor, M. H. Liu, D. X. Qu, R. Cava and N. Ong, Phys. Rev. Lett. 103 (2009).

[4]X. Du, S.-W. Tsai, D. Maslov and A. Hebard, Phys. Rev. Lett. 94 (2005).

[5]N. Marcano, S. Sangiao, M. Plaza, L. Pérez, A. F. n. Pacheco, R. Córdoba, M. C. Sánchez, L. Morellón, M. R. Ibarra and J. M. De Teresa, Appl. Phys. Lett. 96, 082110 (2010).

[6]W. Wang, Y. Du, G. Xu, X. Zhang, E. Liu, Z. Liu, Y. Shi, J. Chen, G. Wu and X. X. Zhang, Scientific reports 3, 2181 (2013).

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