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Surface and bulk electronic structure of aluminium diboride

V. Sunko1,2,*, D. Milosavljević1, F. Mazzola2, O. J. Clark2, U. Burkhardt1, T. K. Kim3, H. Rosner1, Yu. Grin1, A. P. Mackenzie1,2 et al.

P. D. C. King2,†

  • 1Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
  • 2SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, United Kingdom
  • 3Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom

  • *veronika.sunko@cpfs.mpg.de
  • †pdk6@st-andrews.ac.uk
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Phys. Rev. B 102, 035143 – Published 22 July, 2020

DOI: https://doi.org/10.1103/PhysRevB.102.035143

Abstract

We report a combined experimental and theoretical study of the surface and bulk electronic structure of aluminium diboride, a nonsuperconducting sister compound of the superconductor MgB2. We perform angle-resolved photoemission measurements with variable photon energy, and compare them to density functional theory calculations to disentangle the surface and bulk contributions to the measured spectra. Aluminium diboride is known to be aluminium deficient, Al1−δB2, which would be expected to lead to a hole doping as compared to the nominally stoichimoetric compound. Nonetheless, we find that the bulk σ states, which mediate superconductivity in MgB2, remain more than 600meV below the Fermi level. However, we also observe σ states originating from the boron terminated surface, with an order of magnitude smaller binding energy of 70meV, and demonstrate how surface hole-doping can bring these across the Fermi level.

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References (35)

  1. C. Buzea and T. Yamashita, Review of the superconducting properties of MgB2, Supercond. Sci. Technol. 14, R115 (2001).
  2. H. J. Choi, D. Roundy, H. Sun, M. L. Cohen, and S. G. Louie, The origin of the anomalous superconducting properties of MgB2, Nature 418, 758 (2002).
  3. I. Loa, K. Kunc, K. Syassen, and P. Bouvier, Crystal structure and lattice dynamics of AlB2 under pressure and implications for MgB2, Phys. Rev. B 66, 134101 (2002).
  4. U. Burkhardt, V. Gurin, F. Haarmann, H. Borrmann, W. Schnelle, A. Yaresko, and Y. Grin, On the electronic and structural properties of aluminum diboride Al0.9B2, J. Solid State Chem. 177, 389 (2004).
  5. H. Rosner, D. Milosavljević, K. Koch, U. Burkhardt, and Yu. Grin (unpublished).
  6. D. Sharma, J. Kumar, A. Vajpayee, R. Kumar, P. K. Ahluwalia, and V. P. S. Awana, Comparative experimental and density functional theory (DFT) study of the physical properties of MgB2 and AlB2, J. Supercond. Novel Magn. 24, 1925 (2011).
  7. A. Steppke, L. Zhao, M. E. Barber, T. Scaffidi, F. Jerzembeck, H. Rosner, A. S. Gibbs, Y. Maeno, S. H. Simon, A. P. Mackenzie, and C. W. Hicks, Strong peak in Tc of Sr2RuO4 under uniaxial pressure, Science 355, eaaf9398 (2017).
  8. Q. Chen, J. Stajic, S. Tan, and K. Levin, BCS–BEC crossover: From high temperature superconductors to ultracold superfluids, Phys. Rep. 412, 1 (2005).
  9. M. Randeria and E. Taylor, Crossover from Bardeen-Cooper-Schrieffer to Bose-Einstein condensation and the unitary fermi gas, Annu. Rev. Condens. Matter Phys. 5, 209 (2014).
  10. C. Noguera, Polar oxide surfaces, J. Phys.: Condens. Matter 12, R367 (2000).
  11. M. A. Hossain, J. D. F. Mottershead, D. Fournier, A. Bostwick, J. L. McChesney, E. Rotenberg, R. Liang, W. N. Hardy, G. A. Sawatzky, I. S. Elfimov, D. A. Bonn, and A. Damascelli, In situ doping control of the surface of high-temperature superconductors, Nat. Phys. 4, 527 (2008).
  12. Z.-H. Zhu, A. Nicolaou, G. Levy, N. P. Butch, P. Syers, X. F. Wang, J. Paglione, G. A. Sawatzky, I. S. Elfimov, and A. Damascelli, Polarity-Driven Surface Metallicity in SmB6, Phys. Rev. Lett. 111, 216402 (2013).
  13. V. Sunko, H. Rosner, P. Kushwaha, S. Khim, F. Mazzola, L. Bawden, O. J. Clark, J. M. Riley, D. Kasinathan, M. W. Haverkort, T. K. Kim, M. Hoesch, J. Fujii, I. Vobornik, A. P. Mackenzie, and P. D. C. King, Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking, Nature 549, 492 (2017).
  14. F. Mazzola, V. Sunko, S. Khim, H. Rosner, P. Kushwaha, O. J. Clark, L. Bawden, I. Marković, T. K. Kim, M. Hoesch, A. P. Mackenzie, and P. D. C. King, Itinerant ferromagnetism of the Pd-terminated polar surface of PdCoO2, Proc. Natl. Acad. Sci. USA 115, 12956 (2018).
  15. Y. Zhao, C. Lian, S. Zeng, Z. Dai, S. Meng, and J. Ni, Two-gap and three-gap superconductivity in AlB2-based films, Phys. Rev. B 100, 094516 (2019).
  16. S. Hufner, Photoelectron Spectroscopy, Advanced Texts in Physics (Springer, Berlin, 2003).
  17. M. Hoesch, T. K. Kim, P. Dudin, H. Wang, S. Scott, P. Harris, S. Patel, M. Matthews, D. Hawkins, S. G. Alcock, T. Richter, J. J. Mudd, M. Basham, L. Pratt, P. Leicester, E. C. Longhi, A. Tamai, and F. Baumberger, A facility for the analysis of the electronic structures of solids and their surfaces by synchrotron radiation photoelectron spectroscopy, Rev. Sci. Instrum. 88, 013106 (2017).
  18. K. Koepernik and H. Eschrig, Full-potential nonorthogonal local-orbital minimum-basis band-structure scheme, Phys. Rev. B 59, 1743 (1999).
  19. J. P. Perdew and Y. Wang, Accurate and simple analytic representation of the electron-gas correlation energy, Phys. Rev. B 45, 13244 (1992).
  20. J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized Gradient Approximation Made Simple, Phys. Rev. Lett. 77, 3865 (1996).
  21. J. M. An and W. E. Pickett, Superconductivity of MgB2: Covalent Bonds Driven Metallic, Phys. Rev. Lett. 86, 4366 (2001).
  22. D. Takane, S. Souma, K. Nakayama, T. Nakamura, H. Oinuma, K. Hori, K. Horiba, H. Kumigashira, N. Kimura, T. Takahashi, and T. Sato, Observation of a Dirac nodal line in AlB2, Phys. Rev. B 98, 041105(R) (2018).
  23. F. Mazzola, T. Frederiksen, T. Balasubramanian, P. Hofmann, B. Hellsing, and J. W. Wells, Strong electron-phonon coupling in the σ band of graphene, Phys. Rev. B 95, 075430 (2017).
  24. A. Bostwick, T. Ohta, T. Seyller, K. Horn, and E. Rotenberg, Quasiparticle dynamics in graphene, Nat. Phys. 3, 36 (2007).
  25. H. Uchiyama, K. M. Shen, S. Lee, A. Damascelli, D. H. Lu, D. L. Feng, Z.-X. Shen, and S. Tajima, Electronic Structure of MgB2 from Angle-Resolved Photoemission Spectroscopy, Phys. Rev. Lett. 88, 157002 (2002).
  26. S. Souma, T. Sato, T. Takahashi, N. Kimura, and H. Aoki, Electronic band structure of AlB2 studied by angle-resolved photoemission spectroscopy, J. Electron Spectrosc. Relat. Phenom. 144–147, 545 (2005).
  27. A. Damascelli, Probing the electronic structure of complex systems by ARPES, Phys. Scr. T109, 61 (2004).
  28. Y. Sassa, M. Månsson, M. Kobayashi, O. Götberg, V. N. Strocov, T. Schmitt, N. D. Zhigadlo, O. Tjernberg, and B. Batlogg, Probing two- and three-dimensional electrons in MgB2 with soft x-ray angle-resolved photoemission, Phys. Rev. B 91, 045114 (2015).
  29. We note that S1 is degenerate with S2 at the Γ¯ point shown here, and thus the assignment of S1 as a surface state is equally supported by these photon energy-dependent measurements.
  30. D. Mou, R. Jiang, V. Taufour, R. Flint, S. L. Bud'ko, P. C. Canfield, J. S. Wen, Z. J. Xu, G. Gu, and A. Kaminski, Strong interaction between electrons and collective excitations in the multiband superconductor MgB2, Phys. Rev. B 91, 140502(R) (2015).
  31. S. Riccò, M. Kim, A. Tamai, S. M. Walker, F. Y. Bruno, I. Cucchi, E. Cappelli, C. Besnard, T. K. Kim, P. Dudin, M. Hoesch, M. J. Gutmann, A. Georges, R. S. Perry, and F. Baumberger, In situ strain tuning of the metal-insulator-transition of Ca2RuO4 in angle-resolved photoemission experiments, Nat. Commun. 9, 1 (2018).
  32. H. Pfau, C. R. Rotundu, J. C. Palmstrom, S. D. Chen, M. Hashimoto, D. Lu, A. F. Kemper, I. R. Fisher, and Z.-X. Shen, Detailed band structure of twinned and detwinned BaFe2As2 studied with angle-resolved photoemission spectroscopy, Phys. Rev. B 99, 035118 (2019).
  33. V. Sunko, E. A. Morales, I. Marković, M. E. Barber, D. Milosavljević, F. Mazzola, D. A. Sokolov, N. Kikugawa, C. Cacho, P. Dudin, H. Rosner, C. W. Hicks, P. D. C. King, and A. P. Mackenzie, Direct observation of a uniaxial stress-driven Lifshitz transition in Sr2RuO4, npj Quantum Mater. 4, 46 (2019).
  34. C. Hicks, M. E. Barber, S. D. Edkins, D. O. Brodsky, and A. P. Mackenzie, Piezoelectric-based apparatus for strain tuning, Rev. Sci. Instrum. 85, 065003 (2014).
  35. https://doi.org/10.17630/024966a8-67e1-4270-96fe-2f4bd51bea8b.

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Phys. Rev. B 102, 035143– Published 22 July, 2020
  • Received 6 May 2020
  • Accepted 30 June 2020
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

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