Abstract
Topology and superconductivity, two distinct phenomena, offer unique insight into quantum properties and their applications in quantum technologies, spintronics, and sustainable energy technologies. Tin (Sn) plays a pivotal role here as an element because of its two structural phases, α-Sn exhibiting topological characteristics and β-Sn showing superconductivity. Here, we demonstrate precise control of these phases in Sn thin films using molecular beam epitaxy with systematically varied lattice parameters of the buffer layer. The Sn films exhibit either β-Sn or α-Sn phases as the buffer layer's lattice constant varies from 6.10Å to 6.48Å, spanning the range from GaSb (like InAs) to InSb. The crystal structures of α- and β-Sn films are characterized by x-ray diffraction and confirmed by Raman spectroscopy and scanning transmission electron microscopy. Atomic force microscopy validates the smooth, continuous surface morphology. Electrical transport measurements further verify the phases: resistance drop near 3.7 K for β-Sn superconductivity and Shubnikov-de Haas oscillations for α-Sn topological characteristics. Density functional theory shows that α-Sn is stable under tensile strain and β-Sn under compressive strain, aligning well with experimental findings. Hence, this study introduces a platform controlling Sn phases through lattice engineering, enabling innovative applications in quantum technologies and beyond.
| Original language | English |
|---|---|
| Article number | 024202 |
| Journal | Physical Review Materials |
| Volume | 9 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2025 |
Funding
This work was supported by the Science Alliance at the University of Tennessee, Knoxville, through the Support for Affiliated Research Teams program, by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Science and Engineering Division (structural and transport characterization and theoretical investigation by S.Y.) and by the U.S. DOE, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center (M.Y.). T.L., D.L., and H.R. acknowledge the financial support provided by the Global - Learning & Academic research institution for Master's-Ph.D. students, and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (Grant No. RS-2024-00443714). This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. DOE under Contract No. DE-AC05-00OR22725 and resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231 using NERSC award BES-ERCAP0024568. The electron microscopy work was supported by the U.S. National Science Foundation (NSF) CAREER program (Grant No. DMR 2338558). H.K. acknowledges the Nanoscale Research Facility at the Herbert Wertheim College of Engineering at the University of Florida. This work was supported by the Science Alliance at the University of Tennessee, Knoxville, through the Support for Affiliated Research Teams program, by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Science and Engineering Division (structural and transport characterization and theoretical investigation by S.Y.) and by the U.S. DOE, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center (M.Y.). T.L., D.L., and H.R. acknowledge the financial support provided by the Global - Learning & Academic research institution for Master's-Ph.D. students, and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (Grant No. RS-2024–00443714). This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. DOE under Contract No. DE-AC05-00OR22725 and resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231 using NERSC award BES-ERCAP0024568. The electron microscopy work was supported by the U.S. National Science Foundation (NSF) CAREER program (Grant No. DMR 2338558). H.K. acknowledges the Nanoscale Research Facility at the Herbert Wertheim College of Engineering at the University of Florida.