Workshop: Fermi-Surface Topology and Emergence of Novel Electronic States in Strongly Correlated Systems

July 18 to August 01, 2016, in Natal-Brazil

DIRECTORS:

Sebastien Burdin – University Bordeaux (France)
Claudine Lacroix – Institut Néel, CNRS (France)
Sergio Magalhães – Federal University Of Rio Grande Do Sul (Brazil)
Gertrud Zwicknagl – Technische Universität Braunschweig (Germany)

Fermi surfaces occupy a central place in solid-state science, since most of
the physical properties of bulk metallic materials are governed by
conduction electrons. Indeed, the universal Fermi liquid properties that
characterize normal metals at low temperature result from the existence of
a Fermi surface associated with a finite density of electronic states at
the Fermi level. Despite their apparent generality, Fermi surfaces are not
always well defined, even in crystalline electronic systems. This is the
case, for instance, of standard semiconductors where the even electronic
occupancy per site enforces the Fermi level to be inside a band gap.
Several other relevant examples of periodic systems without Fermi surface
have emerged in the last decades due to the discovery of new crystalline
materials where the electrons order topologically. Topological phase
transitions belong to a new class of quantum transitions which cannot be
described by the standard Landau symmetry-breaking theory. Topological
order is characterized macroscopically by a pattern of long range
entanglement which cannot be destroyed by local perturbations. The
existence of such topological ordered states has a strong impact on
technology due to the strength of their quantum coherence.

THE SPECIFIC TOPICS THAT WILL BE COVERED AT THE WORKSHOP ARE:

• Novel materials and experimental methods, including general material
elaboration and characterizations and the two main experimental techniques
for direct probing Fermi Surfaces: Angle Resolved Photoemission (ARPES) and
quantum oscillations (Shubnikov de Haas, de Hass- van Alphen); as well as
indirect but complementary probes such as scanning tunneling microscopy,
soft and hard X-Ray scattering, Inelastic Neutron Scattering (INS), Raman
scattering;

• Novel numerical methods, particularly those related to the necessary
improvements of Density Functional Theory methods that are required for an
ab initio description of materials with a critical Fermi surface;

• Novel analytical methods, that are required for the characterization of
new electronic phases such as unconventional superconductivity, electronic
nematics, strange metals, topological insulators, loop-current, spin-liquid
and non-Fermi liquid phases; and for an appropriate description of
elementary local or collective excitations in these materials;

• Local versus non-local duality of correlated electrons emerging from d
or f orbitals: invoking Mott and Kondo physics, these orbitals may or may
not contribute to the formation of a Fermi surface;

• Lifshitz-like transition and correlations, including the effects
induced by a magnetic field and the coherent lattice effects versus local
correlations;

• Interplay between disorder and Fermi-surface in real materials, in
particular those where doping with foreign element is used to tune the
topology of the Fermi surface; disorder effects resulting from the method
of synthesis (powder versus single crystals, dislocations);

• Artificial matter: cold atoms or quantum dot arrays simulating
correlated electrons on crystalline lattice.

More about the event is available at the IIP website
(www.iip.ufrn.br/events[1])

REGISTRATION FEE:

Students  = US$120,00 / €110,00/ R$400,00
Professionals = US$220,00 / €190,00/ R$700,00

Registration fee: All the participants are expected to pay the registration
fee. Members of the local community (institutions in Natal) are considered
as free listeners and are exempt from paying the fee.

EARLY REGISTRATION DEADLINE: JUNE  01, 2016