Shaken, not stirred: Control Over Complex Systems Consisting of Many Quantum Particles

At TU Vienna, a new method was developed to utilize quantum mechanical vibrations for high precision measurements. The well-known concept of the Ramsey interferometer is applied to a complex multi particle system consisting of hundreds of atoms. Sometimes quantum particles behave like waves. This phenomenon is often used for high precision measurements, for instance in atomic clocks. Usually, only the wave properties of single particles play a role, but now researchers at the Vienna Center for Quantum Science and Technology, Vienna University of Technology have succeeded in quantum mechanically controlling hundreds of Rubidium atoms of an ultracold Bose-Einstein-condensate by shaking it in just the right way. Now, not only internal states of atoms can be used for interferometric measurements, but also the collective motional state of all particles. Superpositions of Different States - According to quantum theory, some physical quantities can only have certain discrete values.