Compact Single Photon Sources in the Visible
Kompakte Einzelphotonquellen im Sichtbaren
Highly sensitive diamond and carborundum nano-sensors and bio-markers with NIR optical addressability
Color centers are a new class of external tags that have exceptionally high output, due to the absence of bleaching or blinking even after months of continuous excitation, yet with an instantaneous brightness comparable to fluorescent proteins. Furthermore, such color centers can be used as nanoscale sensors. A prominent example is the NV defect in diamond, which was shown by the members of DIABASE consortium to be a unique fluorescence label and sensor for magnetic and electric field as well as temperature. We will engineer, investigate and exploit novel color centers in carbon-based materials, like diamond and carborundum (or silicon carbide, SiC), and perform experiments on single-center level in nanomaterials. The accent will be made on the color centers, which are optically active in the near infrared (NIR) spectral region, which is preferential for potential in vivo biological applications due to the deepest tissue penetration. Given biocompatibility of these materials and that color centers remain stable even in atomic-size (few nm) nanocrystals, our approach allows for cellular imaging and sensing at the nanoscale. The principle of sensing is based on variants of the optically detected magnetic resonance technique with single-spin sensitivity. With the use of advanced quantum read-out protocols, magnetic field, electric field, charge, temperature, strain, pressure, forces etc. can be measured with unprecedented accuracy and with nanometer spatial resolution. An ambitious goal, which is not possible with the present-day technologies, is to resolve the structure of single molecules and to follow and visualize chemical reactions in situ. Furthermore, different color centers can be individually addressed due to their distinct spectral activity, allowing for simultaneous sensing of various physical quantities. This implicates novel sensing approach for real-time monitoring of (bio)physical and (bio)chemical processes.
Coherent control techniques for diamond sensors
The goal of this project is to create on the sensor side, the technological prerequisites for the development of a magnetic field sensor operating at room temperature and under ambient conditions (under normal background fields such as earth´s magnetic field). These sensors will be capable of detecting brain activity due to a particular stimulation (e.g. by hearing a sound) and detecting corresponding signals of the auditory cortex.