Dirac and Weyl semimetals

• Applicant: Dr. Sergey Borisenko
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290387256

• Final Report Year: 2020

Final Report Abstract

We have studied the electronic structure of many materials hosting Dirac and Weyl states. We have obtained new and surprising results leading to discovery of several Dirac and Weyl semimetals. Among them are the magnetic type-II Weyl semimetal YbMnBi2, noncetrosymmetric type-II Weyl semimetal TaIrTe4 with minimal number of Weyl points, strongly correlated superconductor Fe-Se-Te with polytypic 3D-Dirac points, basic Z2 topological semimetal GaGeTe, non-magnetic half-metal IrBiSe, several structural modifications of PtBi2 hosting triple Dirac points and superconductivity. Many of the topological materials found have great application potential. ARPES experiments carried out during the project led to the invention of a new type of electron spectrometer which allows the fastest high-resolution mapping of the Fermi surface, in particular of the topological semimetals. First measurements of the Fermi surface of topological insulator Bi2Te3 demonstrate the potential of this novel approach.

Publications

• TaIrTe4: A ternary type-II Weyl semimetal. Phys. Rev. B 93, 201101(R) (2016)
  K. Koepernik, D. Kasinathan, D. V. Efremov, Seunghyun Khim, Sergey Borisenko, Bernd Büchner, and Jeroen van den Brink
  
• Experimental realization of type-II Weyl state in noncentrosymmetric. Phys. Rev. B 95, 241108(R) (2017)
  Haubold, K. Koepernik, D. Efremov, S. Khim, A. Fedorov, Y. Kushnirenko, J. van den Brink, S. Wurmehl, B. Büchner, T. K. Kim, M. Hoesch, K. Sumida, K. Taguchi, T. Yoshikawa, A. Kimura, T. Okuda and S. V. Borisenko
  
• Possible origin of linear magnetoresistance: Observation of Dirac surface states in layered PtBi2. S. Phys. Rev. B 97, 035133 (2018)
  S. Thirupathaiah, Y. Kushnirenko, E. Haubold, A. V. Fedorov, E. D. L. Rienks, T. K. Kim, A. N. Yaresko, C. G. F. Blum, S. Aswartham, B. Büchner, and S. V. Borisenko
  
• Spectroscopic evidence of topological phase transition in the three-dimensional Dirac semimetal Cd3(As1−xPx)2. Phys. Rev. B 98, 085145 (2018)
  S. Thirupathaiah, I. Morozov, Y. Kushnirenko, A. V. Fedorov, E. Haubold, T. K. Kim, G. Shipunov, A. Maksutova, O. Kataeva, S. Aswartham, B. Büchner and S. V. Borisenko
  
• Absence of Dirac fermions in layered BaZnBi2. Phys. Rev. Materials 3, 024202 ( 2019)
  S. Thirupathaiah, D. Efremov, Y. Kushnirenko, E. Haubold, T. K. Kim, B. R. Pienning, I. Morozov, S. Aswartham, B. Büchner and S. V. Borisenko
  
• Possible experimental realization of a basic Z2 topological semimetal in GaGeTe. APL Mater. 7, 121106 (2019)
  Erik Haubold, Alexander Fedorov, Florian Pielnhofer, Igor Rusinov, Tatiana Menshchikova, Viola Duppel, Daniel Friedrich, Richard Weihrich, Arno Pfitzner, Alexander Zeugner, Anna Isaeva, Setti Thirupathaiah, Yevhen Kushnirenko, Emile Rienks, Timur Kim, Evgueni Chulkov, Bernd Büchner and Sergey Borisenko
  
• Time-reversal symmetry breaking type-II Weyl state in YbMnBi2. Nature Communications 10, 3424 (2019)
  Sergey Borisenko, Daniil Evtushinsky, Quinn Gibson, Alexander Yaresko, Klaus Koepernik, Timur Kim, Mazhar Ali, Jeroen van den Brink, Moritz Hoesch, Alexander Fedorov, Erik Haubold, Yevhen Kushnirenko, Ivan Soldatov, Rudolf Schäfer and Robert J. Cava
  
• A Giant Bulk-Type Dresselhaus Splitting with 3D Chiral Spin Texture in IrBiSe. Phys. Status Solidi RRL 14, 1900684 (2020)
  Zhonghao Liu, Setti Thirupathaiah, Alexander Yaresko, Satya Kushwaha, Quinn Gibson, Wei Xia, Yanfeng Guo, Dawei Shen, Robert Cava and Sergey Borisenko
  
• Strongly correlated superconductor with polytypic 3D Dirac points. npj Quantum Materials 5, 67 (2020)
  Sergey Borisenko, Volodymyr Bezguba, Alexander Fedorov, Yevhen Kushnirenko, Vladimir Voroshnin, Mihai Sturza, Saicharan Aswartham and Alexander Yaresko