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Axel Grabowski

Publications and source records attributed to Axel Grabowski.

3 recordsLinked to original sources

Apparatus for excitation and detection of Rydberg atoms in quantum gases

We present and characterize a versatile experimental setup which allows for excitation and detection of Rydberg atoms in quantum gases. The novel concept of the setup features two charged particle detectors and eight electrical field plates inside the vacuum chamber, which allows the detection and manipulation of Rydberg atoms. The setup presented here is applicable to all atomic species used in the field of quantum gases. We describe and characterize the production of Bose-Einstein condensates, the excitation scheme into Rydberg states, the detection of Rydberg states by field ionization followed by ion detection and the various electric field configurations provided by the eight field plates.

quant-ph

High Resolution Rydberg Spectroscopy of ultracold Rubidium Atoms

We present experiments on two-photon excitation of ${\rm ^{87}}$Rb atoms to Rydberg states. For this purpose, two continuous-wave (cw)-laser systems for both 780 nm and 480 nm have been set up. These systems are optimized to a small linewidth (well below 1 MHz) to get both an efficient excitation process and good spectroscopic resolution. To test the performance of our laser system, we investigated the Stark splitting of Rydberg states. For n=40 we were able to see the hyperfine levels splitting in the electrical field for different finestructure states. To show the ability of spatially selective excitation to Rydberg states, we excited rubidium atoms in an electrical field gradient and investigated both linewidths and lineshifts. Furthermore we were able to excite the atoms selectively from the two hyperfine ground states to Rydberg states. Finally, we investigated the Autler-Townes splitting of the 5S$_{1/2}$$\to$5P$_{3/2}$ transition via a Rydberg state to determine the Rabi frequency of this excitation step.

quant-ph

A lattice of Magneto-Optical and Magnetic traps for cold atoms

We describe basic periodic trapping configurations for ultracold atoms above surfaces. The approach is based on a simple wire grid and can be scaled to provide large arrays of periodically arranged magnetic or magneto-optical traps. The unit cells of the trap lattices are based on crossed wire segments. By alternating the current directions in the wires of the grid it can be distinguished between 3 basic lattice configurations. As a first demonstration, we used macroscopic wires in a 2 layer configuration to realize the unit cells of the lattices. With this experimental setup, we observe two of the basic unit cells and an array of 2x2 magneto optical traps.

quant-ph