1. Kinks, Nodal Bilyaer Splitting, and Interband Scattering in YBCO Sergey V. Borisenko “Self-organized Strongly Correlated Electron Systems” 29 May, 2006, Seillac, France

2. THANKS TO: Roland Hübel Martin Knupfer Jörg Fink Andreas Koitzsch Alexander Kordyuk Jochen Geck Bernd Büchner Volodymyr Zabolotnyy Dmitriy Inosov

3. Bernhard Keimer, Chengtian Lin, Vladimir HinkovMPI Stuttgart Yoichi Ando, Shimpei Ono, Seiki KomiyaCRIEPI Tokyo Andreas ErbWMI Garching Helmut BergerEPFL Lausanne Rolf FollathBESSY Sorin Chiuzbaian, Luc PattheySLS Andrey ChubukovU Wisconsin Ilya EreminMPI Dresden Money DFG (Forschergruppe 538) BMBF ("Highest resolution ARPES") EU (LSF Programme) THANKS TO:

4. Angle-Resolved Photoemission Spectroscopy

5. LEED patterns Pb-BSCCOYBCOLSCO

6. Energy Recipe     Bare band structureAuger decayBosons

7. Self-energy Energy

8. Inosov, Zabolotnyy et al. Agreement with experiment Energy A B С A B C

9. G   k) STMRAMANINS

10. LEED patterns Pb-BSCCOYBCOLSCO

11. O. K. Andersen et al. Fermi surface of YBCO Chain states

12. Fermi surface of YBCO

13. Electronic structure of YBCO

15. Nodal bilayer splitting

16. D. H. Lu et al., Phys Rev. Lett 86, 4370 (2001) K. Gofron et al., J. Phys. Chem. Solids 54, 1193 (1993) S Y ГX S bonding antibonding Chain/SS Chain M. C. Schabel et al., Phys. Rev. B 57, 6090 (1998) D. H. Lu et al., Phys Rev. Lett 86, 4370 (2001) Chain Surf. State “hump” SC peak Some of the previous work on YBCO ?

17. YBCO: Gap? Doping level? YBCO 6.85 ~N~A

18. Electronic structure of YBCO 19 meV

19. Temperature dependence. V. Zabolotnyy et al.

20. overdoped Superconducting component superconducting bonding antibonding experiment sum // Model: =0.5*(ABSC + ABN) + BBSC + BBN + Background V. Zabolotnyy et al.

21.  =0.16  =0.30 e-e- e-e-

42.  =0.02  =0.16 Edwards et al, Phys. Rev. Lett. 70, 2967 (1992)

43. ~12 A

44. Momentum dependence of the renormalization in YBCO-6.6 Momentum, ky Momentum, kx V. Zabolotnyy et al.

45. Superconducting gap: anisotropy V. Zabolotnyy et al.

46. Experiment Model Momentum, ky Momentum, kx Momentum dependence in Ca-YBCO 200510 SLS\Ca-YBCO V. Zabolotnyy et al.

47. Temperature dependence in Ca-YBCO. 2005 10 SLS\Ca-YBCO files 014-21 V. Zabolotnyy et al.

48. Kinks in YBCO: nodal direction h =50eVh =53eVh =55eV PRL 06 c

49. Momentum (Å -1 ) PRL 06 c Kinks in YBCO: nodal direction

50. Kinks in YBCO as a function of doping P. Bourges, B. Keimer et al. PRL 06 c

51. YBCO 30 K Kordyuk et al. Cond-mat/0510760

52. Evidence for the strong interband scattering in YBCO PRL 06 b, PRL 06 c

53. Conclusions Methodological conclusions: ARPES spectra of YBCO consist of two components: a strongly overdoped one (top bilayer) and a nominally doped one (second bilayer) There are no other misterious „surface states“ It is possible to enhance the nominally doped component (photon energy, polarization, geometry, Ca-doping) Physical conclusions: Fermi surface of YBCO is consistent with LDA predictions (bilayer splitting, chain states, shape, topology) Renormalization below Tc is strong and anisotropic Superconducting gap has the absolute values comparable to BSCCO and similar anisotropy Kink energy is doping dependent and tracks that of the magnetic excitations‘ spectrum Strong interband scattering, as in BSCCO, indicates that the scattering mediators are the spin fluctuations

54. Synchrotron Light Rolf FollathBESSY Berlin Luc PattheySLS Villigen Funding DFG (Forschergruppe 538), EU (LSF Programme) Thanks to: ARPES of HTSC, Leibniz-IFW Dresden: Alexander Kordyuk, Andreas Koitzsch, Vladimir Zabolotnyy, Jochen Geck, Dmitriy Inosov, Roland Hübel, Jörg Fink, Martin Knupfer, Bernd Büchner Collaboration Bernhard Keimer, Vladimir Hinkov, Chengtian LinMPI Stuttgart Yoichi Ando, Shimpei Ono, Seiki Komiya CRIEPI Tokyo Andrey ChubukovU Wisconsin Ilya EreminMPI Dresden Andreas ErbWMI Garching Helmut BergerEPFL Lausanne