Aktuellste Preprints
Heating a quantum dipolar fluid into a solid
arXiv:2209.00335
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Raising the temperature of a material enhances the thermal motion of particles. Such an increase in thermal energy commonly leads to the melting of a solid into a fluid and eventually vaporises the liquid into a gaseous phase of matter. Here, we study the finite-temperature physics of dipolar quantum fluids and find surprising deviations from this general phenomenology. In particular, we describe how heating a dipolar superfluid from near-zero temperatures can induce a phase transition to a supersolid state with a broken translational symmetry. The predicted effect agrees with experimental measurements on ultracold dysprosium atoms, which opens the door for exploring the unusual thermodynamics of dipolar quantum fluids.
Observation of low-field Feshbach resonances between 161Dy and 40K
arXiv:2207.03407
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We report on the observation of Feshbach resonances at low magnetic field strength (below 10 G) in the Fermi-Fermi mixture of 161Dy and 40K. We characterize five resonances by measurements of interspecies thermalization rates and molecular binding energies. As a case of particular interest for applications, we consider a resonance near 7.29 G, which combines accurate magnetic tunability and access to the universal regime of interactions with experimental simplicity. We show that lifetimes of a few 100 ms can be achieved for the optically trapped, resonantly interacting mixture. We also demonstrate the hydrodynamic expansion of the mixture in the strongly interacting regime and the formation of DyK Feshbach molecules. Our work opens up new experimental possibilities in view of mass-imbalanced superfluids and related phenomena.
Interaction Between an Optically Levitated Nanoparticle and Its Thermal Image: Internal Thermometry via Displacement Sensing
arXiv:2209.11642
Enhancing Detection of Topological Order by Local Error Correctio
arXiv:2209.12428
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More Preprints
The exploration of topologically-ordered states of matter is a long-standing goal at the interface of several subfields of the physical sciences. Such states feature intriguing physical properties such as long-range entanglement, emergent gauge fields and non-local correlations, and can aid in realization of scalable fault-tolerant quantum computation. However, these same features also make creation, detection, and characterization of topologically-ordered states particularly challenging. Motivated by recent experimental demonstrations, we introduce a new approach for quantifying topological states -- locally error-corrected decoration (LED) -- by combining methods of error correction with ideas of renormalization-group flow. Our approach allows for efficient and robust identification of topological order, and is applicable in the presence of incoherent noise sources, making it particularly suitable for realistic experiments. We demonstrate the power of LED using numerical simulations of the toric code under a variety of perturbations, and we subsequently apply it to an experimental realization of a quantum spin liquid using a Rydberg-atom quantum simulator. Extensions to the characterization of other exotic states of matter are discussed.
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Research Groups
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The research group led by Rainer Blatt investigates quantum processes in a system of few ions held in ion traps. The experiments aim at achieving complete control over all quantum degrees of freedom in...
Quantum Optics and Spectroscopy -
The research team led by Francesca Ferlaino focuses on the study of dipolar quantum phenomena, using strongly magnetic atomic species. In 2012, the group has created the first Bose-Einstein...
Dipolar Quantum Gases -
The research group led by R. GRIMM investigates ultracold particle systems consisting of optically trapped quantum gases at temperatures close to absolute zero. Because of their superb experimental...
Ultracold Atoms and Quantum Gases -
Gerhard Kirchmair’s research group works on superconducting circuits and their application for quantum computation and simulation. Superconducting Josephson junctions are used to realize the quantum...
Superconducting quantum circuits -
The research group led by Hannes Pichler studies quantum optical systems, quantum many-body physics and quantum information. The group aims at laying the theoretical foundations for next generation...
Many-Body Quantum Optics -
The research group led by Oriol Romero-Isart studies topics in the fields of theoretical quantum optics and quantum nanophysics in the context of quantum science and technology. One of the main...
Quantum Nanophysics, Optics and Information -
Wittgenstein awardee Peter Zoller’s research group studies topics in the fields of theoretical quantum optics and atomic physics as well as quantum information and condensed matter theory. The...
Quantum Optics