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Calendar of Physics Talks Vienna
| CoQuS colloquium - Seminar Talk by Matthias Troyer (ETH Zurich) |
| Speaker: | Matthias Troyer (ETH Zurich) |
| Abstract: | -- Applications and validation of quantum devices -- About a century after the development of quantum mechanics we have now reached an exciting time where non-trivial devices that make use of quantum effects can be built. Already there are a number commercial and experimental devices making non-trivial use of quantum effects (including quantum random number generators, quantum encryption systems, analogue quantum simulators and quantum optimizers). In this colloquium I will present validation tests we performed on some of the early analogue quantum devices and will end with an outlook towards universal “digital” quantum computers and their applications
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| Date: | Mon, 07.11.2016 |
| Time: | 16:30 |
| Location: | Lise Meitner Hörsaal, Strudlhofgasse 4, 1st floor, Vienna |
| Contact: | CoQuS Team |
| Exact solution of quantum field theory toy models |
| Speaker: | Prof. Raimar Wulkenhaar (Mathematisches Inst. der Westfälischen Wilhelms-Univ., Münster) |
| Abstract: | Matrix models share all interesting features of quantum field theory: graphical description
and Feynman rules, power counting dimension, regularisation and renormalisation, divergence of the perturbation series. The first half of the talk will discuss that analogy.
In the second half we report on two matrix models where much more is possible: to give
exact non-perturbative formulae for any renormalised correlation function, or at least their reduction to one new special function. We will also describe a map which projects these matrix correlation functions to Schwinger functions of an ordinary quantum field theory.
We are optimistic that in one of the models the Schwinger 2-point functions satisfies the Osterwalder-Schrader axioms. These results were obtained in joint work with
Harald Grosse and partly with Akifumi Sako.
|
| Date: | Tue, 08.11.2016 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, H. Grosse |
| Cyclotron resonance in Dirac-type materials |
| Speaker: | Milan Orlita (Laboratoire National des Champs Magnétiques Intenses - Grenoble, CNRS) |
| Abstract: | Cyclotron motion of electrons in a magnetic field, and the related resonant absorption of light at the cyclotron frequency, is probably the most representative magneto-optical effect, characteristic of any solid with non-zero free charge carrier density. In this talk, I will review selected results of cyclotron resonance measurements done on different materials which host conical (Dirac-type) features within their band structures (e.g., single and multilayer graphene, graphite, gapless HgCdTe, HgTe quantum wells). In contrast to conventional systems with parabolic bands, such materials imply fairly complex, in general multimode, cyclotron resonance response, which allows us get relevant insights into the electronic states of these materials, as well as into particular elastic and inelastic (e.g. Auger) scattering mechanisms. |
| Date: | Tue, 08.11.2016 |
| Time: | 15:00 |
| Duration: | 45 min |
| Location: | Seminarraum DC rot 07 (Freihaus, roter Bereich, 7. OG), Wiedner Hauptstraße 8-10, 1040 Wien |
| Contact: | Andrei Pimenov |
| Two puzzles in the beauty sector of QCD |
| Speaker: | Dmitri Melikhov (Uni Wien) |
| Date: | Tue, 08.11.2016 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Neufeld |
| Discovery of emergent materials for spintronics applications |
| Speaker: | Prof. Dr. Hugo Dil (Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL) Switzerland) |
| Abstract: | Spintronics,
the
use
of
the
spin
of
the
electron
rather
than
its
charge,
bears
significant
promise
to
expand
on
current
technology.
Besides
a
reduced
energy
consumption
and
increased
flexibility,
spintronics
also
can
function
as
the
basis
for
quantum
computing.
To
make
true
on
this
promise,
materials
with
novel
electronic
and
spin
properties
are
required.
In
our
research
we
primarily
focus
on
how
spin-‐orbit
interaction
can
be
used
as
a
powerful
tool
for
creating
novel
properties,
especially
when
combined
with
magnetism
or
correlation
effects.
Spin-‐orbit
interaction
can
also
drive
the
system
to
new
physical
phases
as
exemplified
by
topological
insulators
and
Weyl
semimetals.
Using
various
spectroscopic
techniques
we
explored
a
wide
variety
of
materials
with
different
characteristics.
After
a
brief
introduction
to
the
used
techniques
and
the
scientific
background,
I
will
give
an
overvi |
| Date: | Tue, 08.11.2016 |
| Time: | 16:15 |
| Location: | TU Wien, Freihaus Zeichensaal 3, 7. Stock, Turm A |
| Contact: | Univ.Prof.Dr. Friedrich Aumayr |
| A "liquid-solid" phase transition in a simple model for swarming |
| Speaker: | Prof Elliott Lieb (Princeton University) |
| Abstract: | We consider a non-local shape optimization problem, which is motivated
by a simple model for swarming and other self-assembly/aggregation
models, and prove the existence of different phases. A technical key
ingredient, which we establish, is that a strictly subharmonic function
cannot be constant on a set of positive measure. (With Rupert Frank) |
| Date: | Wed, 09.11.2016 |
| Time: | 14:00 |
| Location: | Erwin Schrödinger International Institute, Boltzmanngasse 9, 1090 Wien, Boltzmann lecture hall |
| Contact: | secr@esi.ac.at |
| Exotic Charged States of Charmonium and Bottomonium |
| Speaker: | Prof. Dr. Simon Eidelman (Budker Institute of Nuclear Physics SB RAS and Novosibirsk State University) |
| Abstract: | We discuss exotic charged states in heavy quarkonia based on recent experimental observations from Belle, BESIII and LHCb. For charmonium they include studies of Z(4430) at Belle and LHCb as well as studies of Z_c(3900) and Z_c(4020) at BESIII. For bottomonium a discovery of Z_b(10610) and Z_b(10650) at Belle is presented. We also briefly report on the observation of some other exotic states of charmonium. both charged, like X(4050) and X(4250), and neutral, like X(3872), whose nature is not yet completely understood. |
| Date: | Wed, 09.11.2016 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Stefan-Meyer-Institut, Boltzmanngasse 3, 1090 Wien, Seminarraum 3-2-08 (2. Stock) |
| Contact: | Prof. Dr. Eberhard Widmann, Dr. Martin Simon |
| Decoherence due to time dilation |
| Speaker: | Caslav Brukner (Univ. Vienna) |
| Abstract: | im Rahmen des Literaturseminars der Gravitationsphysik |
| Date: | Thu, 10.11.2016 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Time dependence of holographic spectral function |
| Speaker: | Lata Joshi (IIT Bombay, India) |
| Abstract: | Using state/geometry map, we have proposed a method to find retarded propagator in generic non-equilibrium states. We discuss the spectral function of a scalar in a class of non-equilibrium states. This class is given in terms of AdS-Vaidya geometry with an arbitrary parameter characterizing the dual state transition from one thermal state to another due to a homogenous quench. In this talk, I will discuss different routes and patterns of spectral function thermalization under various quench duration and scalar momenta. |
| Date: | Thu, 10.11.2016 |
| Time: | 16:00 |
| Location: | SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna) |
| Contact: | Ayan Mukhopadhyay |
| Exploring strong correlations in few-fermion |
| Speaker: | Andrea Bergschneider (Universität Heidelber) |
| Abstract: | Our experimental preparation of few-fermion systems give us full control on the many-body quantum state and allows us to explore few-particle physics in the limit of low entropy. By tailoring the trapping potential and tuning the inter-particle interaction strengths we study strongly correlationed systems with few particles.
I will talk about two examples of strongly correlated systems that we have recently realized in our setup. In the first set of experiments, we prepared an anti-ferromagnetic Heisenberg spin chain consisting of up to four fermions in 1D potential. Our measurements represent the first observation of anti-ferromagnetic ordering without an underlying lattice potential. In another experiment, we prepared two interacting fermions in the ground state of a double-well potential. This system represents the fundamental building block of the Fermi-Hubbard model.
Our current research interest is to increase the size of our systems while keeping the entropy low to study strong correlations in the cross-over to the many-body regime. For probing the system we detect single atoms with spin and spatial resolution. I will report on our progress on a simple detection method that will allow us to directly measure correlations in our systems with arbitrary atom numbers.
|
| Date: | Fri, 11.11.2016 |
| Time: | 11:00 |
| Location: | Atominstitut, Hörsaal, Stadionallee 2, Wien 2 |
| Contact: | J. Schmiedmayer |
| Structures, processes and interactions at solid/liquid interfaces |
| Speaker: | Prof. Dr. Markus Valtiner (Max-‐Planck-‐Institut für Eisenforschung GmbH, Düsseldorf & Technische Universität Bergakademie Freiberg Germany) |
| Abstract: | Structure
and
molecular
dynamics
at
solid/liquid
interfaces
are
central
to
many
applications
and
processes
in
biological
and
technological
areas.
These
range
from
specific
surface/molecule
interactions
in
biological
signaling,
adhesion
and
sensor
applications,
to
energy
storage
and
conversion,
as
well
as
materials
degradation.
Here,
I
will
first
provide
a
detailed
overview
on
the
chemical
physics
and
our
current
understanding
of
solid/liquid
interfaces
and
will
discuss
their
technological
importance.
I
will
then
specifically
detail
how
force
probe
techniques
allow
us
to
study
and
understand
processes
at
solid/liquid
interfaces.
Specific
applications
of
force
probe
techniques
in
the
field
of
corrosion,
electrolyte
structuring
and
the
study
of
dynamic
single
molecule/surface
interactions
will
be
reviewed
in
detail.
Finally,
new
ideas
and
perspectives
for
further
unraveling
structure
and
dy |
| Date: | Fri, 11.11.2016 |
| Time: | 16:00 |
| Location: | Technische Universität Wien, TU-Bibliothek, Resselgasse 4, 5th floor, lecture hall |
| Contact: | Univ.Prof.Dr. Friedrich Aumayr |
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