Projects and Third Party Funding
Contact
Projects and Third Party Funding
Unique Light-Matter Interaction with Two Dimensional Materials: UnLiMIt-2D
Project Description
Controlling light- and matter excitations down to the microscopic scale is one major challenge in modern optics. Applications arising from this field, such as novel coherent- and quantum light sources have the potential to affect our daily life. One particularly appealing material platform in quantum physics consists of monolayer crystals. The most prominent species, graphene, however remains rather unappealing for photonic applications due to the lack of an electronic bandgap in its pristine form. Monolayers of transition metal dichalcogenides compounds comprise such a direct bandgap, and additionally feature intriguing spinor properties, making them almost ideal candidates to study optics and excitonic effects in two-dimensional systems.
unLiMIt-2D aims to establish these materials as a new platform in solid-state cavity quantum electrodynamics. The experiments which we carry out in the project are based on thin layers embedded in high quality photonic heterostructures providing optical confinement:
Firstly, we exploit the combination of ultra-large exciton binding energies, giant absorption and unique spin properties of such materials to study microcavity exciton polaritons. These composite bosons provide the unique possibility to study coherent quantum fluids up to room temperature. It is our believe that establishing bosonic condensation effects in atomic monolayers can lead to a paradigm shift in polaritonics.
Secondly, we study exciton localization in layered materials, with the perspective to establish a new generation of microcavity-based quantum light sources. Light-matter coupling effects will greatly improve the performance of such sources, hence we investigate possibilities of tuning the spectral properties of these localizations via external electric and strain-fields, to gain position control and make use of them as sources of single, indistinguishable photons.
DFG Project “Manybody non-linear and coherent phenomena in optical cavities with embedded van der Waals heterostructures: The bosonic versus the fermionic regime” (Part of priority programme SPP2244)
Project Description
Principal Investigators
Christopher Gies, Institut für Theoretische Physik, Universität Bremen, https://www.itp.uni-bremen.de/ag-gies/
Stephan Reitzenstein, Technische Universität Berlin, https://www.tu.berlin/agquantumdevices
Christian Schneider, Carl von Ossietzky Universität Oldenburg, https://uol.de/quantenmaterialien
We aim to deepen the understanding of the cavity-enhanced optoelectronic properties of multi-layered vdW heterostructures. Our projects’ objectives are:
- Bosonic condensation of cavity polaritons based on dipolar tunable hybrid moiré excitons in the regime of strong light-matter coupling
- Lasing and collective emission effects of hetero bi- and trilayer moiré-trapped excitons in the regime of weak light-matter coupling
- Finite temperature effects and lattice-symmetry breaking correlated phases in the extended Bose-Hubbard model
- Aspects of fermionization and atomic reconstruction: Where does fermionic nature of the building blocks of interlayer excitons shine through? What is the impact of lattice reordering at low twist angles?
Our project combines advanced nanofabrication techniques with cutting edge spectroscopy, including a low-temperature open cavity system. Experimental efforts are supported by dedicated theory work using microscopic manybody models and model Hamiltonians. We interact closely with several partner projects in the SPP, providing technological support and the advancement of theoretical methods.
Quantum Dot-Microcavity solid-state quantum light sources
Project Description
This Project aims at the realization and study of quantum dot based sources of single photons and entangled photon pairs and their application for quantum information science. The microcavities, which we utilize in this project, are specifically designed to enhance the collection of either (polarized) single photons or photon pairs, therefore, allowing us to get a step closer to having a deterministic quantum light source.
In collaboration with our collaborator Prof. A. Predojevic (Stockholm) and Dr. T. Huber (Würzburg) we address the following objectives:
- Utilize elliptical micropillar structures embedding a quantum dot that are capable of enhanced and polarization sensitive collection of single photons;
- Develop and implement micropillar structures embedding a quantum dot that are capable of enhanced collection of photon pairs;
- Realize two-photon resonant excitation in quantum dots embedded in micro-pillar structures;
- generation and characterization of time-bin and multi-photon entangled states of light emitted by a quantum dot.
DFG Project EL POLLO LOCO : ELectrically driven POLariton Lasers based On LOCal topological Order
Project Description
In the project “El Pollo Loco”, we develop topological lasers operated in the strong light-matter coupling regime.
With our collaborator Prof. S. Klembt, University Würzburg, we explore the frontiers of light-matter coupled quantum fluids loaded in optical lattices supporting topologically non-trivial optical modes. The experiments will be conducted both under optical and electrical excitation, and will reveal, how the operation performance of polariton lasers in particular, and cavity microlasers in general can benefit from topological protection.
LANTERN: Light-mAtter coupliNg with Two-dimensional tElluRides
Project Description
The project focuses on fundamental investigations of the optical properties of elementary manybody excitations in atomically thin transition-metal dichalcogenide layers, composed of MoTe2 and MoWTe2 in their semiconducting 2H phase. In collaboration with Prof. M. Syperek, University of Wroclaw, we study light-matter coupling, with a particular emphasize on the formation, dynamic scattering and condensation of exciton-polaritons, emerging in these monolayers, by embedding them in custom-designed dielectric microcavities
tubLan Q.0.: Ein quantengesichertes Campusnetzwerk basierend auf sub-Poissonschen Quantenlichtquellen
Project Description
TubLan Q.0 is a BMBF-funded activity to establish a local area quantum-network in the heart of Berlin. The quantum light sources will be fabricated at QMAT.
https://www.forschung-it-sicherheit-kommunikationssysteme.de/projekte/tublan-q.0
