Spin centers in wideband gap semiconductors such as diamonds and silicon carbides are offering ideal platforms for realization of quantum sensors given their strong optical transitions and long quantum coherence lifetimes.  In diamond, the nitrogen vacancy centers (NV-) are particulary prominent due to their exceptional coherence, high brightness and large spin contrast. In recent years important progress has been made which led to realization of nanoscale, subpicotesla magnetometers, quantum gyroscopes, NMR spectrometers and similar. 

Notably, the sensitivity of these sensors depends on the optical spin readout contrast and the signal strength, which continues to remain a limiting factors preventing widescale adoption of such sensors. In the past, several attempts have therefore been made to improve the sensitivity by improving either of the both factors:  
(i) by improving the host material purity, (ii) photon collection efficiency, (iii) by leveraging spin-to-charge conversion facilitating photoelectric detection, (iv) by laser threshold magnetometry and finally, (v) machine-learning and AI based postprocessing techniques. 

Recently, new charge state initialization techniques have been reported, which help reducing the NV0 background luminescence, allowing to boost the spin readout contrast beyond 46%.  In addition, promising new quantum platforms with intrinsically high spin-contrast have emerged, such as single spin defects in gallium nitride or PL6 divacancy in silicon carbide, offering fascinating new research directions.

The PhD project tends to explore and investigate mechanisms, that allow one to improve the sensitivity beyond current capabilities. The candidate will adopt these theoretical concepts, implement them on the real hardware in a lab environment and experimentally verify in first proof of principle experiments. A final step involves development of functional prototypes, demonstrating practically relevant applications on state-of-the art quantum sensing use-cases including inertial sensing and quantum magnetometry. 
 
The research will involve:

• Work or spin-based quantum systems in wide-band gap semiconductors for magnetometry and  inertial sensing applications 
• Implementation of several quantum protocols for initialization and readout of electron and nuclear spins 
• Development of required magnetic, optical, electrical and RF subsystems 
  
• Experimental work, proof of principle experiments, feasibility studies 
• Building demonstrators, data processing 
• Scientific dissemination (conference proceedings, journal papers, patents)