Professor Friedemann Reinhard, “Positioning and readout for quantum magnetic field sensors”, Caltech

The 4th annual Quantum Engineering Workshop, Caltech, May 30, 2024
Professor Friedemann Reinhard, “Positioning and readout for quantum magnetic field sensors”
Abstract: Quantum sensors are widely recognized as the most promising short-term route to the quantum market, and NV color centers in diamond are a front-runner platform for quantum magnetic field sensors. These can either be extremely small, when consisting of a single atom in diamond, or extremely sensitive, when consisting of a millimeter-sized ensemble of color centers. Single centers have enabled imaging of magnetic fields at the nanoscale. Millimeter-scale ensemble sensors could rival the sensitivity of superconducting sensors in a room-temperature device and could pave the way to large-scale application of magnetoencephalography, to microfluidic NMR spectrometers, or to navigation in GPS-denied environments. Both directions (nano- and millimeter-scale sensors) are
well established by laboratory prototypes, but the existing engineering routes towards mass-fabrication and large-scale application face major challenges. Scanning-probe imaging of magnetic fields requires sophisticated nanofabricated diamond scanning probe tips, ensemble sensors require efficient readout of the spin state, which optical fluorescence readout fails to provide. I will survey the state of the art in both techniques, and will present unconventional solutions to these challenges that my laboratory has recently put forward. For scanning probe imaging, we have developed a scheme that can approach an extended planar diamond into nanometer-scale proximity to a sample, and hence enables scanning probe microscopy in a simplified setup with a commercial diamond substrate rather than a custom nanofabricated tip.
For ensemble sensors, we have put forward a novel scheme to read out the spin state of NV center ensembles by integration into a microwave resonator, which promises to solve several subtle problems of optical readout.
Bio: Friedemann Reinhard is heading the quantum technology research group at the Institute of Physics and the Interdisciplinary Faculty of the University of Rostock [1]. His laboratory is working on nanoscale magnetic resonance spectroscopy using NV centers in diamond, biosensing, and scanning-probe imaging. Prior to this position, he has been running an independent Emmy Noether research group at the Technical University of Munich, following an extended postdoctoral stay at the University of Stuttgart. He obtained a PhD from Université Pierre et Marie Curie Paris in 2009, and a diploma in physics from the Georg-August-Universität Göttingen in 2005.
[1] www.qt.physik....
Informaiton about the event:
www.cpp.edu/fa...
Contact: Dr. Farbod Khoshnoud
[e-mail]
[e-mail]