Research Highlights from 2016-2018

Title, Journal: Anisotropic Superfluid Behavior of a Dipolar Bose-Einstein Condensate, Phys. Rev. Lett. 121, 030401 (2018), What?:  Transport measurements on a dipolar superfluid using a Bose-Einstein condensate of 162Dy with strong magnetic dipole-dipole interactions. By moving an attractive laser beam through the condensate the authors observe an anisotropy in superfluid flow. The observations are in excellent agreement with simulations based on the Gross-Pitaevskii equation and highlight the effect of dipolar interactions on macroscopic transport properties, rendering dissipation anisotropic.  Who?: IQST Postdoctoral Fellow Tim Langen Read more
Title, Journal: Ionic Impurity in a Bose-Einstein Condensate at Submicrokelvin Temperatures", Phys. Rev. Lett. 120, 193401 (2018), What?: A giant Rydberg atom enveloping thousands of ordinary atoms could be used to study ion-atom interactions at ultralow temperatures. To suppress the typically dominant electron-neutral interaction, Rydberg states with a principal quantum number up to n=190 are excited from a dense and tightly trapped micron-sized condensate. The results may open up ways to enter the quantum regime of ion-atom scattering for the exploration of charged quantum impurities and associated polaron physics, Who?: IQST Fellow Tilman Pfau Read more
Title, Journal: State-to-state chemistry for three-body recombination in an ultracold rubidium gas, Science Nov 2017, What?: A collaboration between German and American scientists successfully resolved elemental steps in the formation of molecules in one of the simplest chemical reactions, the three-body recombination. For the first time, the scientists are able to quantitatively determine the quantum state distribution of the final products immediately after the three-particle collision in an ultracold gas, Who?:  IQST Fellow Johannes Hecker Denschlag Read more
Title, Journal: Polarization-entangled photons from an InGaAs-based quantum dot emitting in the telecom C-band, Applied Physics Letters Sep 2017, What?: A new nanoscale technique that uses semiconductor quantum dots to bend photons to the wavelengths used by today’s popular C-band standards. “We have demonstrated the emission of polarization-entangled photons from a quantum dot at 1550 nanometers for the first time ever,” said Simone Luca Portalupi, Who?:  IQST YR S. Portalupi,  IQST Fellow P. Michler Read more
Title, Journal: Quantum-Dot Single-Photon Sources for Entanglement Enhanced Interferometry, Physical Review Letters, What?: The authors demonstrate superresolving phase measurements based on two-photon N00N states generated by quantum dot single-photon sources making use of the Hong-Ou-Mandel effect on a beam splitter. A quantum enhanced improvement of the precision in phase uncertainty is achieved which is higher than prescribed by the standard quantum limit. Who?:  IQST Fellow P. Michler Read more
Title, Journal: Nanoscale nuclear magnetic resonance with chemical resolution, Science, What?:  The authors achieve chemical shift resolution in 1H and 19F NMR spectroscopy with a 20 zeptoliter sample volume, by combining the use of a quantum memory and high magnetic fields with a dedicated quantum sensor based on nitrogen vacancy centers in diamond.  Who?: IQST GS M. Pfender, IQST PI P. Neumann, IQST Fellows J. Wrachtrup  Read more
Title, Journal: Submillihertz magnetic spectroscopy performed with a nanoscale quantum sensor, Science, What?:  A quantum spectroscopic technique, coined Qdyne, is introduced in which the spectral resolution is independent of the sensor coherence time (T2) and an enhanced precision scaling of T–3/2 is obtained. By applying Qdyne to shallow NV centers in diamond, we achieved an increase in frequency precision and resolution by nine and eight orders of magnitude, respectively, over the dynamic decoupling technique.  Who?: IQST GS Ilai Schwartz, IQST YR B. Naydenov, IQST PI L. McGuinness, IQST Fellows M. Plenio, F. Jelezko Read more
Title, Journal: Higgs mode and its decay in a two-dimensional antiferromagnet, Nature Physics, What?: Neutron scattering experiments on a two-dimensional antiferromagnet revealed a well-defined, dispersive "Higgs" mode that modulates the amplitude of the ordered moment and decays into transverse spin waves at a rate that depends strongly on the excitation momentum, Who?: IQST Fellow B. Keimer  Read more
Title, Journal: Scalable Quantum Photonics with Single Color Centers in Silicon Carbide, Nano Letters, What?: A scalable array of nanopillars incorporating single silicon vacancy centers in 4H-SiC is developed, which can be readily interfaced with free-space objectives and lensed-fibers , Who?: IQST Fellow J. Wrachtrup Read more
Title, Journal: Measuring broadband magnetic fields on the nanoscale using a hybrid quantum register, Nature Nanotechnology, What?: The magnetic field generated by a hard-disk-drive write head is measured with high spatial resolution and large bandwidth by coherent control of single electron and nuclear spins, Who?: IQST PIs P. Neumann, D. Dasari, IQST Fellow J. Wrachtrup  Read more
Title, Journal: Tracking the coherent generation of polaron pairs in conjugated polymers, Nature Communications, What?: Ultrafast two-dimensional electronic spectroscopy reveals that coherent vibronic coupling induces ultrafast polaron pair formation, accelerates the charge separation dynamics and makes it insensitive to disorder. These findings open up new perspectives for tailoring light-to-current conversion in organic materials. Who?: IQST Fellow S.F. Huelga, M.B. Plenio Read more
Title, Journal: Simultaneous Faraday filtering of the Mollow triplet sidebands with the Cs-D1 clock transition, Nature Communications, What?: A tailored Faraday anomalous dispersion optical filter is presented, which can be used as a key component for the successful link between QD photons and atoms in a hybrid quantum system, Who?: IQST YR S. Portalupi, IQST PIs I. Gerhardt, M. Jetter, IQST Fellows P. Michler, J. Wrachtrup  Read more
Title, Journal: Atom-Chip Fountain Gravimeter, Physical Review Letters, What?: A high-contrast BEC interferometer, realized in a volume as little as a one centimeter cube, paves the way for measurements with sub-μ Gal accuracies in miniaturized, robust devices , Who?: IQST Fellows W. Schleich Read more
Title, Journal: Self-bound droplets of a dilute magnetic quantum liquid, Nature, What?: Stable self-bound droplets of a dilute magnetic quantum liquid made up of dysprosium atoms have been observed. Who?: IQST PI: I. Ferrier-Barbut, IQST Fellow T. Pfau Read more
Title, Journal: Sensing the quantum limit in scanning tunnelling spectroscopy, Nature Communications, What?:  The effect of charge quantization and the resulting interaction with the local environment limits the ultimate energy resolution in scanning tunneling spectroscopy, Who?: IQST PIs C. Ast, M. Etzkorn, IQST Fellows J. Ankerhold, K. Kern  Read more
Title, Journal: Fluorescent Nanodiamond-Gold Hybrid Particles for Multimodal Optical and Electron Microscopy Cellular Imaging, Nano Letters, What?: Confocal and optical coherence microscopy of the fluorescent nanodiamond-gold nanoparticles allow for fast investigations inside living cells via emission, scattering and photothermal imaging techniques,  Who?:  IQST YR B. Naydenov, IQST Fellows F. Jelezko, U. Kaiser, T. Weil, J. Wrachtrup Read more
Title, Journal: Ultracold Chemical Reactions of a Single Rydberg Atom in a Dense Gas, Physical Review X, What?: A thorough and unprecedented study of Rydberg-neutral atom collisions in an ultracold environment is achieved; presented are experiment results for the Rydberg collisional lifetimes for a variety of expeirimental parameters of interest, and a theoretical model for the observed by-products of the resulting chemical reaction, Who?: IQST PI R. Löw, IQST Fellow T. Pfau Read more
Title, Journal: Three-body interaction of Rydberg slow light polaritons, Physical Review Letters, What?:  The influence of the three-body repulsion on bound states and correlation functions of photons propagating through a one-dimensional atomic cloud is derived, Who?:  IQST PI: K. Jachymski, IQST Fellow H.P. Büchler Read more
Title, Journal: Ultrasensitive Magnetometer using a Single Atom, Physical Review Letters, What?: Using a single atomic ion as a sensor, the authors experimentally attain a sensitivity close to the standard quantum limit, even at high frequency fields, by adapting a dynamical decoupling scheme that allows for extending T2 by orders of magnitude and merging it with a magnetic sensing protocol. Who?: IQST Fellow M.B. Plenio Read more
Title, Journal: Quantum Metrology Enhanced by Repetitive Quantum Error Correction, Physical Review Letters, What?: A long-lived nuclear spin is used to correct multiple phase errors on a sensitive electron spin in diamond and realize magnetic field sensing beyond the time scales set by natural decoherence, Who?: IQST YR B. Naydenov, IQST Fellows M.B. Plenio, F. Jelezko  Read more