[17p-K102-1~12] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

3:45 PM - 4:00 PM JST(6:45 AM - 7:00 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[17p-K102-9] Optimized growth condition and quantum oscillation of topological semimetal Sb

〇Tomoki Hotta¹, Le Duc Anh^1,2, Masaaki Tanaka^1,2 (1.Univ. of Tokyo, 2.CSRN, Univ. of Tokyo)

Keywords:

topological semimtal,Sb,quantum oscillation

In this work, we optimize the MBE growth conditions for Sb on GaSb(111)A and observe Shubnikov-de Haas (SdH) oscillations originating from a hole pocket of the Sb Fermi surface, which is a signature of coherent quantum transport of the bulk carrier. The sample structure studied consists of Sb (1 μm) / GaSb (100 nm) / GaSb(111)A substrate. We varied the substrate temperature (T_sub) for Sb layer. When we grew Sb at T_sub = 60°C, reflection high energy electron diffraction (RHEED) patterns showed asymmetric streaks, indicating epitaxial growth without twin structures. After the growth of 5-nm-thick Sb, the sample was annealed at T_sub = 260°C for 30 minutes. Finally, we grew 1-μm-thick Sb at T_sub = 200°C. At 2 K, we observed giant positive magnetoresistance of about 100,000% and clear SdH oscillations. Analysis of the SdH oscillations following the Lifshitz-Kosevich theory allows us to estimate the effective mass of 0.125m₀, Berry phase of 0.825, and quantum mobility of 4460 cm²/Vs of the observed Fermi surface. These results demonstrate the high quality of our Sb thin film thanks to the optimized growth conditions and method.