Berlin 2015 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 7: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems 1 (joint session TT/ DY)

DY 7.4: Vortrag

Montag, 16. März 2015, 10:30–10:45, H 0104

Mechanism of Ultrafast Relaxation of a Photo-Carrier in Antiferromagnetic Spin Background — •Lev Vidmar — University of Munich, Germany

Understanding of relaxation dynamics in correlated condensed-matter systems is vital for identification of dominant couplings in pump-probe experiments, as well as for designing setups where ordered phases are manipulated using external fields.. In many cases, phonons represent an important relaxation channel, however, in two-dimensional systems with antiferromagnetic correlations, this relaxation channel may not be the dominant one [1]. By applying state-of-the-art numerical simulations of the t-J model [2] we show that the relaxation due to coupling to antiferromagnetic spin excitations can be very fast [3]. We show that the key relaxation mechanism at very short times corresponds to the creation of high-energy antiferromagnetic excitations in the close proximity of the photo-excited holes. Such a mechanism enables an energy transfer of more than 1 eV on a 10 femtosecond time scale.

[1] L. Vidmar, J. Bonca, T. Tohyama, and S. Maekawa,

Phys. Rev. Lett. 107, 246404 (2011).

[2] M. Mierzejewski, L. Vidmar, J. Bonca, and P. Prelovsek,

Phys. Rev. Lett. 106, 196401 (2011).

[3] D. Golez, J. Bonca, M. Mierzejewski, and L. Vidmar,

Phys. Rev. B 89, 165118 (2014).