Integrated Quantum Photonics group

(Group leader: Dr. Michael Kaniber)

                                                                                                                                              

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Welcome to the Kaniber-group at Walter Schottky Institut! Our young group is part of the Finley-Labs for "Semiconductor Nanostructures and Quantum Systems" (Prof. J. J. Finley) and consists of highly-motivated, enthusiastic and curiosity driven junior and senior researchers working on various aspects of emerging semiconductor based nano-photonic systems. 

 

Our research focuses on the understanding, control and manipulation of light-matter-interactions between semiconductor quantum materials with reduced dimensionality and high-quality, lithographically engineered nano-photonic environments, eventually down to the single quantum level. For this purpose, we combine quantum dots, nanowires and novel, atomically thin semiconductor crystals with photonic crystal nanostructures or nano-plasmonic waveguides and antennas. Alongside the interest in the fundamental electronic, quantum optical and mechanical aspects of the involved individual entities, we are further driven by the goal of on-chip integration for testing new concept of future nano-photonic circuitry. Therefore, our typical approach combines modern nano-fabrication methods, like electron-beam and Helium-ion beam lithography, with high-quality nanomaterials and ultra-fast quantum optical laser spectroscopy. Our motivation is to gain new insights into the physical mechanisms of the various nanoscopic systems, study and control their interplay and shed light on their potential for novel real-world applications.

 

Current research activities:


Plasmonic nano-channels for light

Guiding and controlling the flow of light on true nanoscale dimensions is one of the dreams in the research field of nano-optics, usually hindered by restrictions due to Abbe’s diffraction limit. Here, nanostructured metallic waveguides have been suggested as one possible solution and in this project we integrate monolayers of atomically thin transition metal di-chalcogenides on lithographically defined gold slot waveguides. Our paramount aim is the understanding and optimization of the light-matter-interaction on the sub-100nm scale and eventually the evaluation of the potential for an on-chip nanoscale coherent laser source.

 

Nanoscale plasmonic antennas

Metallic nano-particles offer the unique ability to concentrate far-field radiation into volumes of only a few cubic nanometres and as a result of that give rise to extraordinarily enhanced electromagnetic near-fields. Those two aspect makes metallic nano-particles a versatile tool to enhance the light-matter-coupling with optically active semiconductor nano-materials and, thus, show enormous potential in ultra-small sensors, strongly enhanced (quantum) light sources and novel applications in non-linear quantum photonics. Here, we study the optical coupling of bowtie nanoantennas and antenna arrays with various semiconductor light sources, such as InGaAs quantum dots or atomically thin MoSe2 crystals. Moreover, we work towards nano-mechanically tuneable nano antennas in combination with electrical readout for future studies in quantum plasmonics applications.
 

On-chip single photon detectors

Patterned superconducting thin films have recently been exploited for realizing high-efficiency, ultra-fast and broadband photon detectors with the capability to detect light down to the single photon level. Combining those superconducting single photon detectors (SSPDs) with semiconductor based nano-photonic hardware paves the way towards fully integrated optical circuits including quantum light sources, photonic hardware and detectors on the very same chip. In this project, we establish optimized SSPDs with photon-number resolving capabilities on semiconducting III-V-, insulating SiO2- and piezoelectric LiNbO3-substrates, integrate them with engineered nanophotonic hardware, such as waveguides or interferometers, and study their interaction with on-chip light sources, like single quantum dots or two-dimensional crystals.
 

Photonics crystals

Photonic crystals (PhC) consist of regularly patterned arrays of materials with different dielectric constants, giving rise to a photonic band structure of light in a similar manner than a periodic Coulomb potential acts on electrons. In particular, two-dimensional PhCs have been well-established in recent years and provide a platform for integrated quantum-photonic applications including nano-cavities, waveguides, splitters and interferometers. Here, we study the light-matter-interaction between individual InGaAs quantum dot and highly localized photonic fields inside single and coupled PhC defect cavities. The high quality of state-of-the-art PhC nanocavities allows to investigate both the weak and strong coupling regime, yield interesting and novel insights into solid-state cavity quantum electrodynamics.

 

Collaborative research activities:

Nanowire lasers

Semiconductor nanowires grown by solid-source molecular beam epitaxy provide inherently the means for waveguiding due to partial reflection from the nanowire end facets. This has recently been exploited to realized III-V-based semiconductor nanolasers, even in a standing configuration directly grown on technologically important silicon substrates. Here, we study the optical response of single nanowire lasers with the goal of understanding the formation and distribution of gain inside the nanowire, the underlying coherence properties and their integration in next-generation on-chip circuits. This project is performed in close collaboration with the Koblmüller-group

 

2D crystals
In close collaboration with the Müller-group we study fundamental opto-electronic properties of mono- to few-layer atomically thin two-dimensional crystals, such as transition metal di-chalcogenides or hexagonal boron nitride, applying advanced optical spectroscopy methods such as magneto-photoluminescence, non-linear optical and pump-probe spectroscopy. The main goal is to probe and understand the basic electrical, (quantum-) optical, mechanical and chemical properties of those emergent nano-materials and evaluate their suitability for incorporation into engineered nano-photopic environments. [more information]

 

Funding:

                          

 

Open Positions:

We are always looking for highly motivated students who would like to work in the field of solid-state based nano-photonics. Interested applicants should contact Dr. Michael Kaniber for an informal discussion on the opportunities available in the Integrated Quantum Photonics Group. More details on currently available topics for Bachelor-, Master- and PhD-projects can be found here.

 

TUM Technische Universität München TUM Technische Universität München Physik Department Elektrotechnik und Informationstechnik TUM Technische Universität München
 

Contact

Dr. Michael Kaniber
Tel.: +49 89 289 12782
Office: S212
Email: michael.kaniber@wsi.tum.de