ANR Project Colector

Collective excitations in topological matter (COLECTOR), December 2019–December 2022

Project coordinator: Dr. Frédéric TEPPE
Russian project coordinator: Prof. Vladimir GAVRILENKO

Collective excitations in topological matter represent a novel field of research focusing on the combined effects of the non-trivial topology of energy bands and electron-electron interactions. To date, there has been little experimental work on Dirac plasmons at the surface of topological insulators, and many other collective excitations, such as spin-plasmons, plasmon-polaritons, or plasma waves, have never been studied. These collective modes are expected to exhibit the non-trivial properties of topological materials with Dirac-type band dispersion. Thus, topological collective excitations are expected to be even more useful for future applications than the well-known quantized conductance of topological states.

The main objective of the project is therefore to evaluate, both theoretically and experimentally, the influence of non-parabolicity and band inversion on electron-electron interactions in topological and Dirac matter, as well as the potential of these new collective excitations to create ultra-efficient sources and detectors in the mid-infrared and terahertz regions. Various collective phenomena will therefore be studied in semiconductor heterostructures known for their topological properties and the relativistic kinetics of their charge carriers: (i) intra-band plasmons, (ii) inter-band plasmons, (iii) plasmonic instabilities, (iv) electron-electron interactions under a magnetic field.

The COLECTOR consortium brings together French and Russian teams with complementary and internationally recognized expertise, both in the physics of electron-electron interactions and topological phases, as well as in the growth of Dirac materials. HgCdTe-based heterostructures will be manufactured in Russia by one of only three groups in the world with the necessary expertise, while InAs/GaSb quantum wells will be grown in France by one of the world leaders in the field.

Project partners

Partner 1: Charles Coulomb Laboratory, UMR5221 CNRS & Montpellier University, France
Partner 2: Institute of Electronics and Systems, UMR5214 CNRS & Montpellier University, France
Partner 3: LPENS Physics Laboratory of the École Normale Supérieure (UMR 8023) of the ENS and CNRS, France
Partner 4: LNCMI National Laboratory for Intense Magnetic Fields, UPR 3228 CNRS, France
Partner 5: Institute for Physics of Microstructures, Russian Academy of Sciences, Russia