講演情報
[17p-K102-9]Optimized growth condition and quantum oscillation of topological semimetal Sb
〇Tomoki Hotta1, Le Duc Anh1,2, Masaaki Tanaka1,2 (1.Univ. of Tokyo, 2.CSRN, Univ. of Tokyo)
キーワード：
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 (Tsub) for Sb layer. When we grew Sb at Tsub = 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 Tsub = 260°C for 30 minutes. Finally, we grew 1-μm-thick Sb at Tsub = 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.