Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 96: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems II

TT 96.3: Talk

Thursday, April 3, 2014, 15:30–15:45, HSZ 304

Quantum quenches and and statistics of projective quantum measurements — •Jonathan Lux and Achim Rosch — Institut für Theoretische Physik, Universität zu Köln

Recently, it became possible to determine the position of ultracold atoms in a 2d optical lattice with single-site resolution[1]. This was used to perform time dependent projective quantum measurements in a many particle system.

Motivated by this development, we study a quench in the 2d XXZ Heisenberg model, where the initial state is a 1d chain of, for example, up-spins in a bath of down-spins. Here the zoology of quasiparticles and their reaction schemes are very rich. After a weak quench, the density of excitations induced by the quench is very low. This allows for a semiclassical approach: the creation and the scattering of the quasiparticles are quantum mechanical, while they propagate classically[2]. Using this method, we study the non-equilibrium statistics of projective quantum measurements, and find that many projective observables show algebraic long-time tails.
T. Fukuhara, et al., Nature Phys. 9, 235 (2013).
S. Sachdev, and K. Damle, PRL 78, 943 (1997).