A5029678041- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Advanced Frequency and Time Standards
- Atomic and Molecular Physics
- Quantum Information and Cryptography
- Orbital Angular Momentum in Optics
- Advanced Chemical Physics Studies
- Quantum optics and atomic interactions
- High-pressure geophysics and materials
- Quantum Mechanics and Applications
- Radio Astronomy Observations and Technology
- Strong Light-Matter Interactions
- Electrohydrodynamics and Fluid Dynamics
- Spectroscopy and Quantum Chemical Studies
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Mechanical and Optical Resonators
- Dark Matter and Cosmic Phenomena
- Microfluidic and Capillary Electrophoresis Applications
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Advanced Fiber Laser Technologies
- Atomic and Subatomic Physics Research
- Advanced Physical and Chemical Molecular Interactions
- Laser-Matter Interactions and Applications
Centre for Quantum Technologies
2022
University of Freiburg
2007-2021
University of Kassel
2020-2021
Universität Innsbruck
2011-2012
We have studied interspecies scattering in an ultracold mixture of $^{87}$Rb and $^{133}$Cs atoms, both their lowest-energy spin states. The three-body loss signatures 30 incoming s- p-wave magnetic Feshbach resonances over the range 0 to 667 G been catalogued. Magnetic field modulation spectroscopy was used observe molecular states bound by up 2.5 MHz$\times h$. moment along magneto-association pathway from 197 182 gives results consistent with observed calculated dependence binding energy...
We perform one- and two-photon high resolution spectroscopy on ultracold samples of RbCs Feshbach molecules with the aim to identify a suitable route for efficient ground-state transfer in quantum-gas regime produce quantum gases dipolar molecules. One-photon loss allows us probe deeply bound rovibrational levels mixed excited (A(1)Σ(+)-b(3)Π)0(+) molecular states. Two-photon dark state connects initial rovibronic ground state. determine binding energy lowest level |v'' = 0, J'' 0> X(1)Σ(+)...
The electronic and motional degrees of freedom trapped ions can be controlled coherently coupled on the level individual quanta. Assembling complex quantum systems ion by while keeping this unique control remains a challenging task. For many applications, linear chains in conventional traps are ideally suited to address problem. However, driven motion due magnetic or radio-frequency electric trapping fields sometimes limits performance one dimension severely affects extension higher...
We report on the realization of a chip-based multipole ion trap manufactured using microelectromechanical systems technology, requiring minimal manual alignment electrodes. It provides confinement in an almost field-free volume between two planes radiofrequency electrodes, deposited glass substrates, which allows for optical access to trap. An analytical model effective trapping potential is presented and compared with numerical calculations. Stable argon ions achieved, lifetime 16 s...
Abstract A quantum sensing protocol is proposed for demonstrating the motion-induced chirality of circularly polarised Rydberg atoms. To this end, a cloud atoms dressed by bichromatic light field. This allows to exploit long-lived ground states implementing Ramsey interferometer in conjunction with spin echo pulse sequence refocussing achiral interactions. Optimal parameters dressing lasers are identified. Combining dipole transition atom atomic centre-of-mass motion, system becomes chiral....
We present single-shot electron velocity-map images of nanoplasmas generated from doped helium nanodroplets and neon clusters by intense near-infrared mid-infrared laser pulses. report a large variety signal types, most crucially depending on the cluster size. The common feature is two-component distribution for each single-cluster event: A bright inner part with nearly circular shape corresponding to energies up few eV, surrounded an extended background more energetic electrons. total...
We report on the observation of time-resolved quantum beats in helium fluorescence from transition 1s3p -> 1s2s, where initial state is excited by XUV free-electron laser radiation. The originate Zeeman splitting magnetic substates due to an external field. perform a systematic study this effect and discuss possibilities studying phenomenon x-ray regime.
The efficient suppression of autoionizing collisions is a stringent requirement to achieve quantum degeneracy in metastable rare gases. Here, we report on the Penning ionization between He and laser-excited Li atoms. Our results show that achieved by conservation both total electron spin $\mathrm{\ensuremath{\Lambda}}$, i.e., projection molecular orbital angular momentum along internuclear axis. findings suggest $\mathrm{\ensuremath{\Lambda}}$ can be used as more general means reaction...
We report on single Barium ions confined in a near-infrared optical dipole trap for up to three seconds absence of any radio-frequency fields. Additionally, the lifetime visible is increased by two orders magnitude as compared state-of-the-art using an efficient repumping method. characterize state-dependent potentials and measure upper bound heating rate trap. These findings are beneficial entering regime ultracold interaction atom-ion ensembles exploiting bichromatic traps. Long lifetimes...
<title>Abstract</title> The dynamics of an x-ray ionized two-component core-shell nanosystem is experimentally probed using doped helium (He) nanodroplets. First, a soft pump pulse selectively inner-shell ionizes the core cluster heavy rare-gas atoms, causing electron migration from He shell to highly-charged core. This leads strong damping cluster’s spatial expansion. Thus, droplets act as tamper that reduces radiation damage embedded nanostructures, property could be exploited for...
The dynamics of an x-ray-ionized two-component core-shell nanosystem is probed using doped helium (He) nanodroplets. First, a soft x-ray pump pulse selectively inner-shell ionizes the core cluster formed heavier rare-gas atoms, causing electron migration from He shell to highly charged core. This ignites nanoplasma which then driven by intense near-infrared probe pulse. ultrafast charge redistribution, evidenced rise He$^+$ and He$^{2+}$ ion yields within $<70$ fs, leads strong damping...
We present a novel planar multipole radiofrequency (rf) ion trap built with microfabrication technologies on transparent substrate. Simulations were performed using an analytical model of the effective potential to determine trapping capabilities different designs. Based upon these simulations was designed, fabricated and successfully characterized in first experiments at ultra high vacuum conditions.
A quantum sensing protocol is proposed for demonstrating the motion-induced chirality of circularly polarised Rydberg atoms. To this end, a cloud atoms dressed by bichromatic light field. This allows to exploit long-lived ground states implementing Ramsey interferometer in conjunction with spin echo pulse sequence refocussing achiral interactions. Optimal parameters dressing lasers are identified. Combining dipole transition atom atomic centre-of-mass motion, system becomes chiral. The...
We report on a high-resolution spectroscopic survey of 6Li40K molecules near the 2S + 4P dissociation threshold and produce fully empirical representation for B1Π potential by connecting available short- long-range data. The purpose is to identify suitable intermediate state coherent Raman transfer absolute ground state, creation molecular gas with dipolar interactions. Starting from weakly bound ultracold Feshbach molecules, transition frequencies twenty-six vibrational states are...
We report on a high-resolution spectroscopic survey of 6 Li 40 K molecules near the 2S + 4P dissociation threshold and produce fully empirical representation for B 1 Π potential by connecting available short-and long-range data.The purpose is to identify suitable intermediate state coherent Raman transfer absolute ground state, creation molecular gas with dipolar interactions.Starting from weakly bound ultracold Feshbach molecules, transition frequencies twenty-six vibrational states are...