Multi-conditioned controlled growth of CoBi nanostructures on SrTiO3
Desheng Cai1,2, Yumin Xia1,2, Pengju Li1,2, Kun Xie1,2, Yuzhou Liu1,2, Yitong Gu1,2, Gan Yu1,2, Changgan Zeng1,2,3, Ping Cui1,3, Shengyong Qin1,2,3()
1. International Center for Quantum Design of Functional Materials (ICQD), University of Science and Technology of China, Hefei 230026, China 2. CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei 230026, China 3. Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
Cobalt pnictides have been theoretically proposed to be attractive candidates for high-temperature superconductors. Additionally, monolayered CoX (X = As, Sb, Bi) on SrTiO3 systems present a potential new platform for realizing topological superconductors in the two-dimensional limit, due to their nontrivial band topology. To this end, we have successfully fabricated high-quality CoBi nanoislands on SrTiO3 (001) substrates by molecular beam epitaxy followed by an investigation of their atomic structure and electronic properties via in situ scanning tunneling microscopy/spectroscopy. Beyond the previously predicted lattice with a = b = 3.5 Å, 2 × 1 dimer row was observed in this study. Furthermore, our results reveal that the topography of CoBi islands is strongly influenced by various growth conditions, such as substrate temperature, the flux ratio between Co and Bi, and the annealing process. This study paves the way for further explorations of the superconductivity and topological properties of cobalt pnictide systems.
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