title: Neue Materialien errechnen: HPC in der Vorhersage neuartiger elektronischer und magnetischer Eigenschaften auf der Nanoskala mittels atomistischer quantenmechanischer Simulationen
Creators: name: Pentcheva, Rossitza
name: Gruner, Markus
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2017
Subjects: subject: 530

description: Der vorliegende Artikel illustriert den Beitrag der theoretischen Materialphysik im Bereich Hochleistungsrechnen mit dem Fokus auf Materialien für elektronische Bauelemente sowie für die Energiegewinnung (Thermoelektrika), Energiespeicherung (Wasserspaltung) und Wärmetransport (magnetische Kühlung).
description: State-of-the-art supercomputers
have meanwhile become an indispensable
tool in the quest for new
materials addressing the technological
challenges of our society. One
important strategy is a knowledgebased
search relying on the understanding
of materials properties on
the electronic scale with parameterfree,
material-specific calculations in
the framework of density functional
theory. This method yields an accurate,
quantum-mechanical access to
materials properties, which is independent
from experiment but in turn
also very computationally expensive,
in particular, when the size of investigated
systems becomes large. Further
challenges concern the treatment
of electron-electron interactions.
Within this contribution, we
illustrate how high performance
computing contributes to this task
using three paradigmatic examples
related to interface-induced electronic
and magnetic phases, materials
for energy harvesting and magnetic
refrigeration. Transition metal oxide
heterostructures not only allow us to
combine functional properties in one
composite material, but, most
importantly, novel electronic states
can be stabilized at their interfaces
that are not available in the bulk
parent compounds. In this contribution
we show how the functionality at the interface can be tailored
exploring systematically a set of
parameters such as polar discontinuities
that can give rise to 2D conductivity
and/or magnetic phases
between insulators. Moreover, strain
and confinement can tune the electronic
behavior between a metal and
an insulator. Last but not least, buckled
honeycomb patterns in oxide
superlattices can lead to exotic topologically
nontrivial states that bear
analogies to graphene with additional
functionality due to the correlated
nature of d and f-electrons.
Furthermore, we demonstrate how
strain can be used to enhance the
thermoelectric performance of
highly anisotropic cobalt delafossites.
In future, one may thus expect
to exploit spin- and orbital degrees
of freedom in the design of electronic
devices or the development of
highly efficient thermoelectric generators. The third example aims at
the intimate coupling between magnetic,
lattice and electronic degrees
of freedom in modern magnetocaloric
materials. Their understanding is
of primary importance for the development
of energy-saving refrigeration
and air-conditioning concepts.
description: UNIKATE: Berichte aus Forschung und Lehre, no. 50Natur-, Ingenieur- und Wirtschaftswissenschaften - High-Performance und Cloud Computing, p. 86