Dear Colleague,

we are pleased to announce the Workshop

Excitonic insulator: New perspectives in long-range interacting systems,
CECAM Headquarters, Lausanne (Switzerland) 3-5 September 2018.

Workshop abstract:

Fifty years ago a few outstanding physicists, including Leonid Keldysh and the Nobel prize recipient Walter Kohn, put forward a heretic paradigm of a strongly correlated insulator: If a narrow-gap semiconductor (or a compensated semimetal) failed to fully screen its intrinsic charge carriers, then excitons--electron-hole pairs bound together by Coulomb attraction---would spontaneously form. This would destabilize the ground state, leading to a reconstructed ‘excitonic insulator’ that would exhibit a distinctive broken symmetry, inherited by the exciton character, as well as peculiar collective modes of purely electronic origin. So far, the observation of this phase has been elusive. Very recently, novel low-d systems seem to renew the promise of the excitonic insulator, as they combine truly long-ranged interactions and giant excitonic effects. By collecting the key actors of theoretical and experimental research, who are spread among different communities, this Workshop aims at the in-depth analysis of common themes and challenges, both theoretical and computational, to establish a roadmap to the excitonic insulator.

Information and abstract submission:

Full information on the workshop is available at https://www.cecam.org/workshop-0-1562.html . Oral presentations are by invitation only. Abstract submissions are open until 15 June 2018 through the workshop website (please include title and abstract). The program timetable will cover three full working days, including a poster session with short poster presentation talks. All participants will have their workshop fees waived.

Invited speakers:

Peter Abbamonte: TBA

Dario Bercioux: Quantum transport properties of an exciton insulator/superconductor hybrid junction

Leonid Butov: Condensation of indirect excitons

Pierluigi Cudazzo: Cumulant expansion of the electronic polarizability: Beyond the static Bethe-Salpeter equation

Joaquin Drut: Scale anomalies in low-dimensional non-relativistic matter

Rui-Rui Du: TBA

Jim Eisenstein: Exciton condensation and transport in a bilayer quantum Hall system

Holger Fehske: On the existence and nature of the excitonic insulator phase in the extended Falicov-Kimball model

Marcel Franz: TBA

Denis Golez: Photo-manipulation of band gap in excitonic insulator

Maria Hellgren: TBA

Igor Herbut: Three-dimensional Luttinger semimetal and its interacting phases

Dmitri Khveshchenko: Holographic description of excitonic phenomena

Jan Kunes: Excitonic magnetism in strongly correlated materials

Peter Littlewood: Excitons, plasmons, and phonons in SrTiO₃

Allan MacDonald: Anatomy of exciton condensates in double bilayer graphene

Valerio Olevano: Insight from ab initio many-body GW into the possible excitonic insulator phase of TiSe₂

Francois Peeters: TBA

Ajay Sood: Insights into excitonic insulator Ta₂NiSe₅by temperature and pressure dependent Raman scattering

Sandro Sorella: Correlation-driven dimerization and gap opening in isotropically strained graphene

Tineke Stroucken: TBA

Jasper van Wezel: Collective modes of the excitonic condensate in TiSe₂

Daniele Varsano: TBA

With best regards,

Massimo Rontani and Elisa Molinari