Início
Agenda 

 09 de dezembro de 2015
16h30 F210 

Prof. Andreas Klümper

University of
Wuppertal


Correlation
functions of integrable quantum spin chains

Integrable systems like the spin1/2 Heisenberg
chain provide the rare opportunity of calculating exact results
like energies and thermodynamics for finite size and in the
thermodynamic limit. We know many integrable systems for many
decades, but actual calculations of physical properties have
only rather recently been done if at all. 

A notorious problem is posed by the computation of
correlation functions. For the infinite volume system, even
static correlators present a major challenge. Currently, we know
how to calculate short range correlators for the spin1/2
Heisenberg chain at arbitrary temperature and magnetic field,
where the first results for zero temperature and zero magnetic
field have been obtained about 20 years ago. A central result of
Jimbo, Miwa, Smirnov and others is the factorization of general
static correlators into sums over products of nearestneighbour
correlators similar to the Wick theorem for ideal quantum
systems however with much more complicated structure factors.


There are applications in the field of
nonequilibrium systems such as interaction quenches. I will
talk about applications of the computational methods for
thestudy of the stationary state approached through the
equilibration process. A major subject of my talk will be the
generalization of the study of correlation functions in
direction of higher spinS chains with su(2) symmetry and into
the direction of higher rank symmetry like su(3).




