ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT wigner.mta.hu>]

MEGHÍVÓ

Wigner SZFI Kvantumoptika és Kvantuminformatika Csoport szemináriuma
Május 20, kedd, 13 óra, SZFI Tanácsterem
Ujfalusi László, BME

Quantum percolation transition in 3d: density of states, finite size
scaling and multifractality

Abstract:
Since the seminal work of Anderson we know, that disorder plays an
important role of conductivity properties of a system. For the
investigation of structural disorder percolation is one of the most
important and widely used models. With increasing disorder extended states
of a perfect crystal turn into localized states through a second order
phase transition, called Anderson-transition. At criticality the system is
scale-free, leading to multifractal eigenstates of the Hamiltonian. We used
this spectacular property of the wave functions to identify the mobility
edge, the energy-dependent critical point of the quantum percolation model.
The critical exponent of the localization length was found to be
\nu=1.627+-0.055,
in very good agreement with the one for the Anderson-model confirming, that
these models belong to the same universality class. The multifractal
exponents were also determined, and we found certain deviations from our
expectations. The very special density of states of the model will also be
presented along with its special chiral molecular states at the band center.

http://arxiv.org/abs/1405.1985

Szeretettel várjuk az érdeklődőket,
 Asbóth János