Research
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 trapped 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
Entanglement of atoms in microwave near-field potentials
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]
Ultracold atoms coupled to mechanical oscillators
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]
Microwave field imaging with ultracold atoms
In this experiment, we use ultracold atoms for high-resolution imaging of microwave fields near integrated microwave circuits. [more]
Former projects
Atomic clock and coherence close to a chip surface
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]