Snapshots of the retarded electronic interaction with spin-fluctuations in high-temperature superconductors

Condensed Matter Seminars

Speaker: Claudio Giannetti, i-Lamp & Università Cattolica, Brescia, Italy
Date & Time: January 23, 2014 14:00 - 15:00
Location: UBC, Hennings 318
Local Contact: Andrea Damascelli
Intended Audience: Graduate

One of the pivotal questions in the physics of high-temperature superconductors, that is whether there is any boson mediating the low-energy dynamics of the charge carriers [1, 2]. This issue has been hitherto elusive since electronic correlations are expected to dramatically speed up the electron-boson scattering processes, confining them to the very femtosecond timescale that is difficultly accessible even by established ultrafast techniques [3-6]. Here we simultaneously push the time-resolution and the frequency-range of transient reflectivity measurements up to the unprecedented level of directly observing the ~15 fs build-up of the effective electron-boson interaction in doped copper oxides. This extremely fast timescale, together with the outcome of calculations within the t-J model and the repulsive Hubbard model, indicates that short-range spin fluctuations are the universal class of bosons mediating the retarded electron interactions in copper oxides with doping concentration close to that necessary to attain the largest critical temperature.

[1] P. W. Anderson, Science 316, 1705 (2007).
[2] D. Scalapino, Review of Modern Physics 84, 1383 (2012). [3] J. Orenstein, Physics Today 65 (2012).
[4] C. Giannetti et al., Nat. Commun. 2, 353 (2011).
[5] S. Dal Conte et al., Science 335, 1600 (2012).
[6] G. Coslovich et al., Phys. Rev. Lett. 110, 107003 (2013).