7) Special technologies, sensing

Our development of quantum technologies aims at control of charge, flux, phonons, and microwave irradiation at the ultimate accuracy governed by quantum mechanics. Conversion between these quantities can be employed for developing new paradigms and novel sensor applications. Furthermore, quantum coherence, both in superconductors and superfluids, can be harnessed to construct sensitive interferometric detectors, in particular for magnetic flux and rotation, respectively.  A core feature of the quantum realm, quantum entanglement is utilized to develop schemes that reach even below the standard quantum limit in one signal quadrature.

Examples of such sensing technologies range from single electron transistors, Josephson junctions, parametric amplifiers, optomechanical systems, all the way to macroscopic superfluid gyrometers for absolute rotation detection. Recently, we have investigated techniques for creation of correlated pairs of particles, especially controlled creation of spin-entangled electron pairs as well as two-mode-squeezed states of photons. In conjunction with the Centre of Quantum Engineering (CQE), we develop these technological applications on a broad front. Nanocarbon constituents form a materials category of high potential for sensing.

- Cooled CCD cameras for low T imaging [RSI 65, 1784 (1994)]
- Optical interferometry at ULT temperatures [
PRL 74, 2744 (1995)] 
- Rotation detection using helium SQUID [
PRL78, 3602 (1997)]
- Manipulation of nanoparticles by AFM  [APL 73, 21505 (1998)]  
- Charge detection with SET on membrane [JAP 86, 2684 (1999)] 
- Charge sensing with nanocarbon detectors [APL 77, 4037 (2000)]
- Noise detection by Josephson junction [J. Phys Soc. Jpn. (2003)]
- Vibration sensing using optomechanics [APL 95, 011909 (2009)]
- Two-mode-squeezed states [PNAS 110, 4234 (2013)]
- Vibration enhanced charge detection [Nano Lett, 15, 1667 (2015)]