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2018.06.12 isabel guillamon uam

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II Jornada científica NanoFrontMag - 12 de junio de 2018 - IMDEA Nanociencia
Isabel Guillamón
Universidad Autónoma de Madrid

Publicado en: Ciencias
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2018.06.12 isabel guillamon uam

  1. 1. Laboratorio de Bajas Temperaturas Universidad Autónoma de Madrid Unidad Asociada de Bajas Temperaturas y Altos Campos Magnéticos (UAM-CSIC) Imaging pnictide superconductors close to magnetic instabilities via scanning tunneling spectroscopy Isabel Guillamón
  2. 2. Iron-based superconductors J. Paglione and R. L. Green, Nat. Phys. 6, 645-658 (2011) FeAs plane Magnetic order Fe As / Se Li Sr La/Sr O / F Sc 11 111 122 1111 122*
  3. 3. Iron-based superconductors Stripe-like AF order / orthorhombic structure vv vv vv A. Chubukov et al. Physics Today 68 (6), 46 (2015)
  4. 4. Iron-based superconductors M. Rotter, et al., Angew. Chem., Int. Ed., 47, 7949 (2008)
  5. 5. Iron-based superconductors s± pairing Unconventional pairing I. Mazin et al., Rep. Prog. Phys. 74, 124508 (2011) P.J. Hirschfeld et al., C. R. Phys. 17, 197 (2016)
  6. 6. Iron-based superconductors Cho et al. Sci. Adv. 2, 1600807 (2016) ©√ √√ √ √√
  7. 7. Disordered vortex lattice BaFe1.8Co0.2As2 Yin,..,Hoffman, PRL 102 097002 (2009) FeSe Song et al, Science 332 1410 (2011) Ba0.6K0.4Fe2As2 San et al, Nat Phys 7 325 (2011) LiFeAs Hanaguri et al, PRB 85 214505 (2012) Fe(Se,Te) Massee et al, Sci Adv 10 1126 (2015) Fe(Se,Te)
  8. 8. Iron-based superconductors vv vv vv Superconductivity Highest Tc appears in doped compounds Only a few stoichiometric compounds are superconductors A. Chubukov et al. Physics Today 68 (6), 46 (2015)
  9. 9. Iron-based superconductors vv vv vv Superconductivity Highest Tc appears in doped compounds Only a few stoichiometric compounds are superconductors Intrinsic SC properties at optimal Tc? A. Chubukov et al. Physics Today 68 (6), 46 (2015)
  10. 10. Disordered vortex lattice BaFe1.8Co0.2As2 Yin,..,Hoffman, PRL 102 097002 (2009) FeSe Song et al, Science 332 1410 (2011) Ba0.6K0.4Fe2As2 San et al, Nat Phys 7 325 (2011) LiFeAs Hanaguri et al, PRB 85 214505 (2012) Fe(Se,Te) Massee et al, Sci Adv 10 1126 (2015) Fe(Se,Te) Intrinsic pinning mechanism?
  11. 11. Different approaches to these problems Co-doped Ca122 CaKFe4As4P-substituted Ba122 A. Fente et al. PRB 97, 134501 (2018) J. Benito et al., in preparation V. Barrena et al., in preparationA. Fente et al. PRB 97, 014505 (2018)
  12. 12. Different approaches to these problems Co-doped Ca122 CaKFe4As4P-substituted Ba122 A. Fente et al. PRB 97, 134501 (2018) J. Benito et al., in preparation V. Barrena et al., in preparationA. Fente et al. PRB 97, 014505 (2018)
  13. 13. 1144 Fe based superconductors
  14. 14. Fe As / Se Li Sr La/Sr O / F Sc 11 111 122 1111 122* 1144 CaKFe4As4 J. Paglione and R. L. Green, Nat. Phys. 6, 645-658 (2011) W.R. Meier et al., npj Quantum Materials 3, 5 (2018) 1144 Fe based superconductors
  15. 15. 1144 CaKFe4As4 W.R. Meier et al., npj Quantum Materials 3, 5 (2018) Cho, Fente et al. Phys. Rev. B 95, 100502(R) 2017 1144 Fe based superconductors
  16. 16. 1144 CaKFe4As4 W.R. Meier et al., npj Quantum Materials 3, 5 (2018) 1144 Fe based superconductors
  17. 17. 1144 CaK(Fe1-xNix)4As4 W.R. Meier et al., npj Quantum Materials 3, 5 (2018) 1144 Fe based superconductors
  18. 18. Multigap superconductivity in CaKFe4As4 Vortex pinning in CaKFe4As4 Plan Intrinsic HTc mechanism? Intrinsic pinning mechanism?
  19. 19. Dilution refrigerator STM Compact very low temperature STM with mechanically driven horizontal linear positioning state H. Suderow, I. Guillamón and S. Vieira Rev Sci Inst, 033771, 82 (2011) Dilution Fridge Superconducting Magnet B < 22 T Home-made electronics and mechanics. Temperature down to 100 mK and magnetic field up to 22 T. Mechanical pulling system to move the tip over the sample Tip and sample preparation methods
  20. 20. Current falicities at LBTUAM • Dil fridge STM (15 mK)+ 5T-1T-1T (2×102) • Dil fridge STM (30 mK)+ 9T (2×102) • Dil fridge STM (7 mK)+ 9T(9×102) • 4K-cryostat + 17 T (3) • Dil fridge STM (7mK) + 17T (1.6×103) • Dil fridge STM (7 mK) + 22T (2.2×103) Very high magnetic field STM Y.J. Song, et al., Review of Scientific Instruments 81, 121101 (2010).
  21. 21. Current falicities at LBTUAM • Dil fridge STM (15 mK)+ 5T-1T-1T (2×102) • Dil fridge STM (30 mK)+ 9T (2×102) • Dil fridge STM (7 mK)+ 9T(9×102) • 4K-cryostat + 17 T (3) • Dil fridge STM (7mK) + 17T (1.6×103) • Dil fridge STM (7 mK) + 22T (2.2×103) Very high magnetic field STM Y.J. Song, et al., Review of Scientific Instruments 81, 121101 (2010).
  22. 22. Very high magnetic field STM Low Vibration Lab with floating floor High magnetic field STM up to 22 T
  23. 23. Very high magnetic field STM Low Vibration Lab with floating floor High magnetic field STM up to 22 T
  24. 24. Very high magnetic field STM High magnetic field STM up to 22 T Low Vibration Lab with floating floor
  25. 25. Very high magnetic field STM Reaching 22 T without a single quench! Low Vibration Lab with floating floor Bi2Pt B. Wu, V. Barrena et al., in preparation
  26. 26. Very high magnetic field STM High magnetic field STM (22 T, resistive magnets) Low Vibration Lab with floating floor Bi2Pt F. Martín, R. Sánchez, et al. in preparation
  27. 27. Multigap superconductivity in CaKFe4As4 Vortex pinning in CaKFe4As4 Plan Intrinsic HTc mechanism? Intrinsic pinning mechanism?
  28. 28. STM in CaKFe4As4
  29. 29. STM in CaKFe4As4 gi (a.u.) 0 10 D (meV) Multiband superconductor ∆ = ∆(k) å - = i i 2 i 2S (k)ΔE E (E)N g Cho, Fente et al. Phys. Rev. B 95, 100502(R) 2017
  30. 30. Two gap superconductivity Collaboration with group of R. Prozorov (Ames) Cho, Fente et al. Phys. Rev. B 95, 100502(R) 2017 Consistent with s± pairing
  31. 31. Two gap superconductivity Mou et al., PRL 117 277001 (2016) abg d
  32. 32. STM in CaKFe4As4 77 nm A. Fente et al., PRB 97, 134501 (2018)
  33. 33. 2kF STM/S in superconductors Down to atomic scale… Quasiparticle interference: QPI Charge waves by scattering Real space conductance map Energy, bias voltage Wavevector Fourier transform L. Petersen et al. Phys. Rev. B, R6858, 57 (1998) L. Simon, et al., J. Phys. Cond. Matt. 19 (2007) 355009
  34. 34. STM in CaKFe4As4 q A. Fente et al., PRB 97, 134501 (2018)
  35. 35. STM in CaKFe4As4 q A. Fente et al., PRB 97, 134501 (2018)
  36. 36. STM in CaKFe4As4 q A. Fente et al., PRB 97, 134501 (2018)
  37. 37. STM in CaKFe4As4 Scale bars: 82 nm A. Fente et al., PRB 97, 134501 (2018)
  38. 38. STM in CaKFe4As4 r E |∆| ~D2/EF A. Fente et al., PRB 97, 134501 (2018)
  39. 39. STM in CaKFe4As4 C.-L. Song et al., Science 332, 1410 (2011) L. Shan et al., Nature Physics 7, 325–331 (2011) T. Hanaguri et al., Phys. Rev. B 85, 214505 (2012) FeSe (Ba0.6K0.4)Fe2As2 LiFeAs
  40. 40. STM in CaKFe4As4 A. Fente et al., PRB 97, 134501 (2018)
  41. 41. STM in CaKFe4As4 A. Fente et al., PRB 97, 134501 (2018)
  42. 42. STM in CaKFe4As4 4 T 0 meV 120 nm A. Fente et al., PRB 97, 134501 (2018)
  43. 43. STM in CaKFe4As4 A. Fente et al., PRB 97, 134501 (2018)
  44. 44. Collaborators W.R. Meier, S.L. Bud'ko, P.C. Canfield Ames Laboratory and Iowa State University, USA J. Benito, A. Fente, E. Herrera, V. Barrena, B. Wu, F. Martin, R. Sánchez H. Suderow, S. Vieira Laboratorio Bajas Temperaturas, Universidad Autónoma de Madrid P. Walmsley, I.R. Fisher Geballe Laboratory for Advance Materials Stanford University
  45. 45. Imaging pnictide superconductors close to magnetic instabilities via scanning tunneling spectroscopy Thanks for your attention!

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