In our experiments we use "atom chips" to laser-cool, trap, and coherently manipulate neutral atoms at micrometer distances from a chip surface. In our first project, we generate spin-squeezed and other many-particle entangled states of atomic Bose-Einstein condensates (BECs) on the chip, which are interesting for fundamental studies of entanglement as well as for applications in quantum metrology and quantum information processing. In a second project, we use atoms for high-resolution imaging of electromagnetic fields near the chip surface, such as microwave fields from integrated circuits. In the third project, we investigate quantum interfaces between the atoms and solid-state systems such as micro- and nanomechanical oscillators.
Current research projects
In this experiment we use microwave circuits on an atom chip to generate potentials that depend on the internal atomic state. We use the potentials to perform trapped-atom interferometry with two-component BECs. Atomic collisions allow us to prepare spin-squeezed and many-particle entangled states. The techniques developed here are interesting for quantum metrology and quantum information processing. [more]
In this project we couple ultracold atoms to the vibrations of micro- and nanoscale mechanical oscillators. In a first experiment, we have used a BEC to read out the vibrations of a microcantilever. Currently we investigate optomechanical interfaces of atoms and SiN membrane oscillators. One goal is to build hybrid quantum systems in which the atoms are used for cooling, read-out, and coherent manipulation of the oscillator. [more]
In this project, we use atoms for high-resolution imaging of microwave fields near integrated circuits and in atomic clocks, using both ultracold atoms and room-temperature vapor cells. Further applications of our technique are the spatially resolved characterization of atomic diffusion in vapor cells and relaxation by atom-wall collisions. [more]
As a first application of atom chips, we have realized an atomic clock in a chip trap. We have shown that the coherence of atomic superposition states can be maintained for several seconds at micrometer distances from the room-temperature chip surface. This is crucial for applications of atom chips in quantum information processing and precision measurement. [more]