Crystal growth and quantum oscillations in the topological chiral semimetal CoSi

Journal Article · 08 July 2019 · Physical Review B

DOI: https://doi.org/10.1103/physrevb.100.045104 · OSTI ID:1632128

Xu, Xitong ^[1]; Wang, Xirui ^[1]; Cochran, Tyler A. ^[2]; Sanchez, Daniel S. ^[2]; Belopolski, Ilya ^[2]; Chang, Guoqing ^[2]; Wang, Guangqiang ^[1]; Liu, Yiyuan ^[1]; Tien, Hung-Ju ^[3]; Gui, Xin ^[4]; Xie, Weiwei ^[4]; Hasan, M. Zahid ^[5]; Chang, Tay-Rong ^[6]; Jia, Shuang ^[7]

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1. Peking Univ., Beijing (China). School of Physics
2. Princeton Univ., NJ (United States). Dept. of Physics
3. National Cheng Kung Univ., Tainan (Taiwan). Dept. of Physics
4. Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemistry
5. Princeton Univ., NJ (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
6. National Cheng Kung Univ., Tainan (Taiwan). Dept. of Physics; Center for Quantum Frontiers of Research and Technology (QFort), Tainan (Taiwan)
7. Peking Univ., Beijing (China). School of Physics; Collaborative Innovation Center of Quantum Matter, Beijing (China); Univ. of Chinese Academy of Sciences, Beijing (China). CAS Center for Excellence in Topological Quantum Computation; Beijing Academy of Quantum Information Sciences, Beijing (China)

Here, we survey the electrical transport properties of single-crystalline, topological chiral semimetal CoSi grown via different methods. High-quality CoSi single crystals were found in the growth from a tellurium solution. The sample's high carrier mobility enables us to observe quantum oscillations (QOs) in its thermoelectrical signals. Our analysis of QOs reveals two spherical Fermi surfaces around the R point in its Brillouin zone corner. The extracted Berry phases of these electron orbits are consistent with the -2 chiral charge as reported in density functional theory (DFT) calculations. A detailed analysis of the QOs reveals that the spin-orbit-coupling-induced band splitting is less than 2 meV near the Fermi level, one order of magnitude smaller than our DFT calculation. We also report a large phonon-drag-induced Nernst effect in CoSi at intermediate temperatures.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Natural Science Foundation of China (NSFC); National Key Research and Development Program of China; Chinese Academy of Sciences; Ministry of Science and Technology (MOST) Taiwan; National Science Foundation (NSF)
• Grant/Contract Number: AC02-05CH11231; FG-02-05ER46200; U1832214; 11774007; 2018YFA0305601; XDB28000000; MOST108-2636-M-006-002; 107-2627-E-006-001; OIA-1832967
• OSTI ID: 1632128
• Alternate ID(s): OSTI ID: 1546378
• Journal Information: Physical Review B, Vol. 100, Issue 4; ISSN 2469-9950
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English