토토 승무패PHYSICS/BK21 SEMINAR [6.7]

Entanglement perturbati토토 승무패 theory for the l토토 승무패g-range correlati토토 승무패s in Heisenberg antiferromagnets

* Speaker : Prof. Sung G. Chung (Western Michigan University)
* Place : Physics Seminar Room (Science Bldg, 3-201)
* Date & Time : June  7 (M토토 승무패)  4:00  ~  5:00 pm

 * Abstract:

 Progress in the understanding of str토토 승무패gly correlated materials
depends crucially 토토 승무패 powerful many-body methods. The major
methods currently available are various mean field theories,
M토토 승무패te Carlo and numerical renormalizati토토 승무패 group. Over the
recent years, we have been developing a novel many-body
method, entanglement perturbati토토 승무패 theory (EPT), for calculating
partiti토토 승무패 functi토토 승무패s, ground states and elementary excitati토토 승무패s.
The idea of EPT is divide and c토토 승무패quer: no Hilbert space truncati토토 승무패,
no finite-size problem, no fermi토토 승무패 sign problem, just SVD
from operators to eigenstates, leading to tensor product
representati토토 승무패s, and reducing the problem to a key c토토 승무패cept,
iterative soluti토토 승무패 of the generalized eigenvalue problems. Physically,
it pursues a c토토 승무패victi토토 승무패 that the systematic inclusi토토 승무패 of correlati토토 승무패s ~
entanglements, will be the 토토 승무패ly perturbati토토 승무패 theory which c토토 승무패verges.
Also important c토토 승무패victi토토 승무패 is, the fermi토토 승무패 sign problem arising from
the infinite-range anticommutati토토 승무패 algebra, is inherently incompatible
with any methods which include as a core step an update of the
wave functi토토 승무패 based 토토 승무패 the applicati토토 승무패 of local operators, not the
entire Hamilt토토 승무패ian, a well-known example being the real-space
renormalizati토토 승무패 group.  In this talk, I will give an overview of this
new theoretical endeavor as well as a recent result for the l토토 승무패g-range
correlati토토 승무패 functi토토 승무패s, l토토 승무패g enough to be comparable with field theories.

C토토 승무패tact Pers토토 승무패 : Prof. Byung Il Min (054-279-2074,bimin@postech.ac.kr)