Forschungsgruppen
Dipolare Quantengase
Die Forschungsgruppe um Francesca Ferlaino beschäftigt sich mit dipolaren Quantenphänomenen, wofür sie stark magnetische Atomspezies verwendet. So konnte die Gruppe im Jahr 2012 das erste... Read more …
Ultrakalte Atome und Quantengase
Die Arbeitsgruppe unter der Leitung von Rudolf Grimm untersucht ultrakalte Teilchensysteme, bestehend aus optisch gespeicherten Quantengasen sehr nahe am absoluten Nullpunkt. Solche Systeme... Read more …
Supraleitende Quantenschaltkreise
Die Forschungsgruppe um Gerhard Kirchmair arbeitet an supraleitenden Schaltkreisen und deren Anwendung in der Quanteninformationsverarbeitung und Quantensimulation. Die quantenmechanischen... Read more …
Quantenoptik und Vielteilchenphysik
Die Forschungsgruppe unter der Leitung von Hannes Pichler beschäftigt sich mit quantenoptischen Systemen, Quanten-Vielteilchenphysik und Quanteninformation. Ziel der Gruppe ist es, die theoretischen Grundlagen... Read more …
Emeritus Forschungsgruppen
Quantenoptik und Spektroskopie
Die Forschungsgruppe um Rainer Blatt untersucht quantenphysikalische Prozesse an Ionen, die in Ionenfallen gespeichert sind. Ziel der Experimente ist es, eine möglichst vollständige Kontrolle über... Read more …
Quantenoptik und Quanteninformation
Peter Zoller's Forschungsarbeiten sind auf den Gebieten der theoretischen Quantenoptik und Atomphysik, der Quanteninformation und der Theorie kondensierter Materie angesiedelt. Im Vordergrund steht... Read more …
Aktuellste Preprints
Coherent control over the high-dimensional space of the nuclear spin of alkaline-earth atoms
arXiv:2501.01731
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We demonstrate coherent manipulation of the nuclear degrees of freedom of ultracold ground-state strontium 87 atoms, thus providing a toolkit for fully exploiting the corresponding large Hilbert space as a quantum resource and for quantum simulation experiments with SU(N)-symmetric matter. By controlling the resonance conditions of Raman transitions with a tensor light shift, we can perform rotations within a restricted Hilbert space of two isolated spin states among the 2F+1 = 10 possible states. These manipulations correspond to engineering unitary operations deriving from generators of the SU(N) algebra beyond what can be done by simple spin precession. We present Ramsey interferometers involving an isolated pair of Zeeman states with no measurable decoherence after 3 seconds. We also demonstrate that one can harvest the large spin degrees of freedom as a qudit resource by implementing two interferometer schemes over four states. The first scheme senses in parallel multiple external fields acting on the atoms, and the second scheme simultaneously measures multiple observables of a collective atomic state - including non-commuting ones. Engineering unitary transformations of the large spin driven by other generators than the usual spin-F representation of the SU(2) group offers new possibilities from the point of view of quantum metrology and quantum many-body physics, notably for the quantum simulation of large-spin SU(N)-symmetric quantum magnetism with fermionic alkaline-earth atoms.
Synchronization in rotating supersolids
arXiv:2412.11976
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Synchronization is ubiquitous in nature at various scales and fields. This phenomenon not only offers a window into the intrinsic harmony of complex systems, but also serves as a robust probe for many-body quantum systems. One such system is a supersolid: an exotic state that is simultaneously superfluid and solid. Here, we show that putting a supersolid under rotation leads to a synchronization of the crystal's motion to an external driving frequency triggered by quantum vortex nucleation, revealing the system's dual solid-superfluid response. Benchmarking the theoretical framework against experimental observations, we exploit this model as a novel method to investigate the critical frequency required for vortex nucleation. Our results underscore the utility of synchronization as a powerful probe for quantum systems.
Kerr enhanced optomechanical cooling in the unresolved sideband regime
arXiv:2410.15435
Error-corrected fermionic quantum processors with neutral atoms
arXiv:2412.16081
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Many-body fermionic systems can be simulated in a hardware-efficient manner using a fermionic quantum processor. Neutral atoms trapped in optical potentials can realize such processors, where non-local fermionic statistics are guaranteed at the hardware level. Implementing quantum error correction in this setup is however challenging, due to the atom-number superselection present in atomic systems, that is, the impossibility of creating coherent superpositions of different particle numbers. In this work, we overcome this constraint and present a blueprint for an error-corrected fermionic quantum computer that can be implemented using current experimental capabilities. To achieve this, we first consider an ancillary set of fermionic modes and design a fermionic reference, which we then use to construct superpositions of different numbers of referenced fermions. This allows us to build logical fermionic modes that can be error corrected using standard atomic operations. Here, we focus on phase errors, which we expect to be a dominant source of errors in neutral-atom quantum processors. We then construct logical fermionic gates, and show their implementation for the logical particle-number conserving processes relevant for quantum simulation. Finally, our protocol is illustrated using a minimal fermionic circuit, where it leads to a quadratic suppression of the logical error rate.
Derandomized shallow shadows: Efficient Pauli learning with bounded-depth circuits
arXiv:2412.18973
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Mehr Preprints
Efficiently estimating large numbers of non-commuting observables is an important subroutine of many quantum science tasks. We present the derandomized shallow shadows (DSS) algorithm for efficiently learning a large set of non-commuting observables, using shallow circuits to rotate into measurement bases. Exploiting tensor network techniques to ensure polynomial scaling of classical resources, our algorithm outputs a set of shallow measurement circuits that approximately minimizes the sample complexity of estimating a given set of Pauli strings. We numerically demonstrate systematic improvement, in comparison with state-of-the-art techniques, for energy estimation of quantum chemistry benchmarks and verification of quantum many-body systems, and we observe DSS's performance consistently improves as one allows deeper measurement circuits. These results indicate that in addition to being an efficient, low-depth, stand-alone algorithm, DSS can also benefit many larger quantum algorithms requiring estimation of multiple non-commuting observables.
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