Feliciano Giustino - Electron-phonon interaction in copper oxides and iron

Tuesday 16 February 2010, 13:30

Feliciano Giustino, (University of Oxford)

University of Oxford

The electron-phonon interaction is at the origin of conventional superconductivity and is naturally the first possible mechanism to be considered when a new class of superconductors is discovered. In the case of copper oxide superconductors the possibility of an electron-phonon mediated pairing has been ruled out soon after the original discovery, in favour of purely electronic mechanisms. However during the past decade very refined angle-resolved photoemission experiments revealed an intriguing spectral feature called the kink which has been interpreted as the signature of a strong electron-phonon interaction. In the case of iron pnictide superconductors, while early theoretical investigations ruled out a phonon-mediated superconducting pairing, inelastic X-ray scattering experiments revealed interesting phonon renormalization effects, which are a typical signature of strong electron-phonon interactions. To date the role of the electron-phonon interaction in the copper oxides and in the iron pnictides remains controversial. In this talk I will describe some recent efforts to simulate from first-principles angle-resolved photoemission spectra and inelastic X-ray scattering spectra in order to interpret these complex experiments. In particular I will focus on the two prototypical compounds La_{2-x}Sr_xCuO_4 and LaFeAsO_{1-x}F_x. Through these examples I will highlight how state-of-the-art atomic-scale modelling is becoming increasingly necessary to interpret complex spectroscopic data, and how superconductivity research will benefit from a synergistic effort between experiment and computer simulations.

 

[1] F. Giustino, M. L. Cohen, S. G. Louie, Nature 452, 975 (2008).

[2] J. Noffsinger, F. Giustino, S. G. Louie, M. L. Cohen, Phys. Rev. Lett. 102, 147003 (2009).

Event type Seminar
Start date and time Tuesday 16 February 2010, 13:30
End Tuesday 16 February 2010, 14:30
Location CR11, R3
Maximum Audience 25
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