Controlling collective effects in and positioning of nanocrystals, embedded in polymer waveguides for sensing applications

• Applicants: Professor Dr. Georg von Freymann; Professor Dr. Artur Widera
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 454931666

The project will combine recent developments in additive microstructuring with quantum optical control of ensembles of emitters to construct and apply novel integrated sensing devices for magnetic fields. First, the project will develop tools to deterministically embed nanocrystals, concretely nanodiamonds, into three-dimensional polymer waveguides with feature sizes in the micrometer regime. Second, the project will observe, understand, and control the collective effects of nitrogen-vacancy centers. Specifically, we aim at understanding the emergence of superradiance and its short-time dynamics on a fundamental quantum-optical level. Also, we will study the possible cross-talk between sub-ensembles having different dipole-orientation. We will use this knowledge together with spin-to-charge conversion to selectively improve the coupling of NV centers in one nanodiamond to the mode of a polymer waveguide. Third, we will combine this knowledge with recently invented direct laser writing of metallic structures to provide a genuinely integrated magnetic field sensor on the tip of an optical fiber. It will enable the measuring of magnetic fields at the smallest distances in biological or opaque media such as spin-crossover materials, for example. Our project will thus pave the way for local and quantum-optically facilitated magnetic field sensing.

• DFG Programme: Research Grants