Detecting tiny signals using the Quantum Information toolbox: A quantum lock-in measurement of the magnetic interaction of two electrons.
Shlomi Kotler, Weizmann Institute of Science
12/06/2013 - 12:00 - 13:00
Nano center, Seminar room B-032, ground floor
Spectroscopy was a key player in the emergence of experimental Quantum Information Processing. Spectroscopic tools, built on the abilities to isolate and coherently manipulate trapped atomic particles, were used to create Bell pairs, store quantum information for seconds and release it.
In the past few years, spectroscopy had a surprising return on investment. It turns out that the same techniques that are used to generate entanglement are also useful for precision spectroscopy. So useful, in fact, that the best atomic clock to date is based on quantum information techniques.
It is this interesting turn of events that will be the focus of our talk. We will show in theory and experiments how one can use non-commutativity of quantum mechanical operators to enhance spectroscopic measurements. With these techniques we achieved the best magnetic field measurement sensitivity for a single spin (15 pT/√Hz) as well as the detection of the magnetic interaction of two electrons.