Condensed Matter Seminar

Please note different date

Rodrigo Pereira
University of British Columbia

Tuesday, December 11, 2007
1:00 pm in SPL 52

Dynamical correlations of spin-1/2 chains

Abstract: Spin-1/2 chains demonstrate some of the striking effects of interactions and quantum fluctuations in one-dimensional systems. In the critical, quasi-long-range order regime, many of the non-trivial properties of spin-1/2 chains have been explained by effective field theories, with parameters taken from the exact Bethe ansatz solution. However, the standard low-energy approach fails in the calculation of time-dependent correlation functions. This is partly because 1D dynamics seems to depend crucially on high-energy properties, such as integrability. In this talk I will describe how bosonization and Bethe ansatz can be brought together in new methods to calculate dynamical correlations. I will present results on the exact singularities of the dynamical structure factor and on the long-time asymptotics of self-correlation functions which are in good agreement with numerical real-time data from the Density Matrix Renormalization Group (DMRG).