Magneto-transport properties of the ternary topological insulator (Bi$_{0.5}$Sb$_{0.5})_{2}$Te$_{3}$ in the presence of electrostatic gating and magnetic impurity

ORAL

Abstract

A three-dimensional ternary topological insulator, (Bi$_{0.5}$Sb$_{0.5})_{2}$Te$_{3}$, is used to characterize the unique electronic properties of the spin helical conducting surface state. Epitaxial films are grown via MBE on (111) SrTiO$_{3}$ substrate, which serves as the gate dielectric. Magnetoresistance (MR) and Hall effect measurements have been performed in a broad range of back gate voltages. Ambipolar field effect has been observed, enabling effective tuning of the Fermi level across the band gap and identification of the surface transport in the topological transport regime. Weak antilocalization effect is identified and used to differentiate the surface state. The Hikami-Larkin-Nagaoka (HLN) equation is used to analyze the MR data and the results show the top and bottom surfaces become decoupled when the Fermi level is in the bulk band gap. We also examine the effects of paramagnetic impurity (MI), which introduces time reversal symmetry breaking scattering on the TI surface states. Taking advantage of the unique capability of \textit{in situ} deposition of Cr atoms in a customized dilution refrigerator, MI was incrementally quench-condensed onto the sample surface and transport measurements were performed at each MI density. Pronounced changes in the weak antilocalization effect and the sample carrier density with increasing MI concentration were observed. Possible origins of these observations will be discussed.

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Authors

  • Liuqi Yu

    Florida State University

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia

  • Chris Neu

    Florida State University, NHMFL, Institut Neel, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, Florida State University, Department of Physics, Florida State University, Tallahassee, FL, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, Florida State University, National High Magnetic Field Laboratory, Institute of Physics, Chinese Academy of Sciences, China, Austin Peay State University, University of Pardubice, Davidson College, Covenant College, Lookout Mtn, GA 30750, Russian Academy of Sciences, Moscow, RU, University of Tennessee Space Institute, Tullahoma, TN, USA, Sandia National Laboratories,* Albuquerque, NM, Arkansas State University, Jonesboro, AK, None, Mississippi State University, Mississippi State University Department of Physics and Astronomy, Florida State University and the National High Magnetic Field Laboratory, Faculte des Sciences et Techniques and Universite Aix-Marseille, MIT Haystack Observatory, Departments of Chemistry and Physics, University of Tennessee of Chattanooga, Departments of Chemistry and Physics, University of Tennessee at Chattanooga, Western Kentucky University, Thomas Jefferson National Accelerator Facility, Newport News, VA, Fermilab, University of Virginia and Fermilab, Indiana University Bloomington, Indiana University Health Proton Therapy Center, University of North Florida, National Superconducting Cyclotron Laboratory, Michigan State University, Flordia State University, Louisiana State University, Washington University, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Florida State University., JINR, Tsinghua University, LBNL, LBNL/Vanderbilt University, Vanderbilt University, Florida A\&M University, Georgia Institute of Technology, Department of Physics, Virginia Tech, Gatton Academy, Exeter University, Florida International University, Office of Research, University of North Florida, Physics Department, University of North Florida, NSCL, Michigan State University, Physics Department, Florida State University, University of Tennessee-Knoxville, Neel Institut, Kazan Federal University, Bielefeld University, Ben Gurion University, LCIB - CEA, University of Georgia, Lawrence Livermore National Laboratory, Livermore, CA 94550, NHMFL, Tallahassee, USA, Department of Chemistry, University of Waterloo, Ontario, Canada, NHMFL, Tallahassee FL 32310 USA, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, Wigner Research Center for Physics, Budapest, Hungary, Experimental physics II, University of Augsburg, Germany, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, National High Magnetic Field Laboratory Florida State University, Tallahassee, Florida 32310, IM2NP-CNRS (UMR 7334) and Universite Aix-Marseille, National High Magnetic Field Laboratory Applied Superconductivity Center, Heifei National Lab for Physical Science at Microscale, USTC, Institute of Physics, Chinese Academy of Sciences, Department of Electrical Engineering, Rice University, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory/FSU, University of Virginia