Institute for Advanced Study Astrophysics Seminar

The field of experimental quantum information started with the first realization of an entangling gate in 1995. Tools originally developed for precision spectroscopy, turned out extremely useful for generating Bell pairs and storing quantum superposition states for seconds. At the level of very few quantum bits, we can quantum compute. A real large-scale quantum computer, however, is nowhere near to be found. We don't know how to scale the very few to the tens and hundreds. Yet. In this talk I will review some of the progress done in the last 19 years towards quantum computers, from the point of view of an ion experimentalist. We will then focus on a surprising "return on investment" experienced by us spectroscopists. Techniques developed for quantum information now find use in precision and ultra sensitive measurement, most notably the measurement of time with a fractional error of 10^-18. I will demonstrate these ideas in more detail on a particular example, namely, the first measurement of the magnetic interaction between two electrons.