|Round 1||Room number||Abstract|
|Jindaratsamee||Phrompao||1||Cryofuge: cold, dense, slow polyatomic molecules toward cold collisions'|
We would like to present our unique experimental setup that allows for cooling and trapping of many polyatomic molecular species. In our experiment we combine cryo-genic buﬀer gas cooling with centrifuge deceleration  to create a bright, high density ﬂux of cold molecules, namely Cryofuge. With the addition of an electrostatic trap, molecules can now be conﬁned for several seconds, with the goal of studying collisions in more detail.
 X. Wu et al., Science 358, 645-648, (2017).
|Jonathan||Mortlock||2||Durham University: Ultracold Molecule Microscope Lab|
Our lab contains a three species ultracold atom machine for Cs, Rb and K, and we are working towards high resolution imaging of associated polar molecules in optical lattices. Such a system would offer a highly tuneable and versatile platform for quantum simulation. Our apparatus has a two chamber design to improve optical access for a microscope objective and latticfe beams. We currently produce BECs of Cs and Rb, and ultracold 41K, and have recently used our Ti: Sapphire laser to measure the 880nm Cs tune out wavelength. We are currently working on moving optical lattice based transport for atoms and K-Cs mixture experiments.
|Jan||Lowinski||3||In our lab we use cold Rubidium 87 atoms for quantum information processing purposes. In a small ensemble cooled in a magneto-optical trap and trapped in a dipole trap we generate singular Rydberg excitations. Thanks to the collective nature of the excitations we can map them efficiently to single photons in a well defined mode. In our recent experiment we store them in a Raman quantum memory that resides on the neighboring table. It can be seen as a step towards realization of quantum repeaters with deterministic single photon sources and quantum memories.|
|Hauke||Biss||4||Lithium-6 Experiment (Moritz AG, University of Hamburg): In our lab, we study strongly correlated systems of ultracold fermionic lithium-6 atoms. |
After collecting the atoms in a magneto-optical trap, they are transferred into a large volume resonator trap and precooled by direct optical evaporation. Next, they are transferred into a moving dipole trap, transported into a glass cell with excellent optical access and cooled to degeneracy. By loading them into box potentials using precisely tailored optical traps we create either three- or two-dimensional superfluids with homogeneous density. Two microscope objectives with a numerical aperture of 0.6 allow us to imprint arbitrary potentials and image the gases with high optical resolution. By exploiting the broad Feshbach resonance of lithium-6, we can explore the crossover between gases consisting of composite bosonic pairs and gases consisting of fermionic Cooper pairs.
These capabilities have allowed us to study various intriguing many-body properties of strongly correlated superfluids. We have realized Josephson oscillations as well as unambiguously demonstrated the superfluidity of 2D superfluids, observed quantum limited damping of sound and determined the excitation spectrum of 2D and 3D superfluids.
|Oleksiy||Onishchenko||5||Our group is focussing on modern quantum applications with trapped ions. |
For quantum computing, we operate microstructured segmented ion
traps, implement ultrafast ion shuttling operations, fast ion
separations, ion-SWAPs, in combination with laser-driven gate
operations. We use the setup for running quantum algorithms, e.g. fault
tolerant quantum error correction. Also, we are operating a cryogenic
setup for segmented traps. This setup makes it possible to test different ion trap
technologies, such as surface ion traps. Other topics we are working on are
experiments on quantum thermodynamics, Rydberg excitation of ions,
multispecies ion crystal cooling and even shuttling out of the trap for
implantation of dopants, detection of photon correlation quantum
optics, and STED illumination of ions with focused vortex light ﬁelds.
The Ion Trap Group laboratory at Aarhus University (group leader Michael Drewsen)
Join us for a live lab tour in the basement and get a feeling of what it takes to trap, cool and do experiments with ions. We will show you our central laser lab, which provides laser light for ionization, cooling and spectroscopy to the different ion traps in the neighboring rooms. We will also show you 3 of our ion trap setups dedicated to each their ion experiment, called the Molecule Trap, the Cryo Trap and the Blue Cavity Trap. As the names suggest the two former traps are used to do spectroscopy on molecular ions, the latter at cryogenic temperatures (4 K) and the last trap for manipulating the trapped ion position with laser cavity light blue detuned from the Doppler cooling transition.
|Luca||Donini||7||The Kagome lab hosts our cold-atom experiment that will be capable of studying bosons (87Rb and 39K) and fermions (40K) in an optical kagome lattice and imaging them with a quantum gas microscope. The laser system consists of a combination of commercial and home-built diode lasers and amplifiers. The light is manipulated using acousto-optic modulators (AOMs) and delivered to the experiment via optical fibres. The vacuum system is composed of two parts: the MOT chamber, where the atoms are prepared and cooled to quantum degeneracy, and the science chamber, where the kagome physics will be investigated. The atom cloud is optically transported between the two chambers using a focus-tunable lens. The science chamber features a quantum gas microscope, which will allow high-resolution imaging of the lattice.|
The Lattice Laboratory of the Quantum Gas Group at Aarhus University
The Lattice Laboratory at Aarhus University is a Bose-Einstein condensation centered laboratory originally build in the mid 2000's. It achieved its first Bose-Einstein condensation of Rb87 in 2006 and was initially invested in studies of BECs in optical lattices. We have since abandoned optical lattices, and the latest scientific output of the laboratory consists of recently published papers on fundamental atom number fluctuations in BECs.
The MIX laboratory at Aarhus University is capable of producing Bose-Einstein Condensates which are used to investigate complex many-body systems. It is called MIX, because we simultaneously load rubidium and potassium atoms into our cell, which enables us to produce BEC's of both species. However, presently we are using rubidium to sympathetically cool potassium to get a larger BEC of the latter.
The lab itself consists of two tables. One is for the laser system used for cooling and trapping. The other is for the MOT cell as well as the science cell, where our experiments take place."
|Stefan||Spence||3||The optical tweezers lab in Durham started in 2017 with the goal of creating optical tweezer arrays of individual ultracold RbCs molecules. The exquisite control over internal and external degrees of freedom leads to proposed applications in quantum computation, quantum simulation, and quantum chemistry.|
Optical tweezers are optical dipole traps with beam waists on the order of 1 micron. In this tight confinement the collisional blockade can ensure trap occupancies of one or zero atoms only. We use an 814nm tweezer to selectively trap Rb atoms, and a 938nm tweezer which can trap Cs or Rb atoms. We have demonstrated the ability to move the traps and post-select runs where Rb and Cs where successfully merged into the same trap. In order to efficiently associate the atoms into a molecule, they must be in the motional ground state of the trap. This is achieved by Raman sideband cooling, which we are currently optimising for the atomic species separately.
The next steps will be simultaneously applying Raman sideband cooling to both species, before using Feshbach association to reach a molecular state.
|Chih-Han||Yeh||4||We are the "Quantum Clocks and Complex Systems" research group under the guidance of Prof. Dr. Tanja E. Mehlstäubler at the German National Metrology Institute (PTB) in Braunschweig. |
Currently there are four main projects that support each other.
This includes two dedicated Ytterbium ion-trap experiments, a Indium-Ytterbium ion-trap experiment, and the user facility "Ion Traps"of the Quantum Technology Competence Center (QTZ).
In the Ytterbium experiments, we exploit high precision spectroscopy on single to several tens of ions to perform tests of fundamental physics such as local Lorentz invariance and study the rich dynamics of larger ion Coulomb crystals.
The Indium-Ytterbium experiment uses indium ions in mixed-species Coulomb crystals as its frequency reference for an improved signal-to-noise ratio as compared to single-ion clocks. We aim to achieve this scaling without compromising and a systematic uncertainty below 10^-18.
We are also part of the QTZ, which is a research facility unifying the competence in quantum metrology and quantum sensing aiming for strong exchange of knowledge with German industries.
In the user facility "Ion Traps" of the QTZ, next-generation ion traps that are optimized for quantum technology applications, such as portable optical clocks, precision spectroscopy, and quantum simulations are developed and benchmarked.
|Shaurya||Bhave||5||We are the quasicrystal experimental in the MBQD group based at the Cavendish Laboratory at the University of Cambridge. |
In our lab, we are able to generate an eightfold symmetric quasicrystal by overlapping 4 (non-interfering) 1D lattice beams at 45 deg to each other. This creates a novel lattice with rotational symmetry that is usually forbidden by the crystallographic theorem. Thus, the potential we create has the property that it is long-range ordered but not periodic.
This enables to study the various transport property of atoms in such a potential.
Besides this we are also able to do experiments in a regular 3d cubic lattice with the help of our Z lattice beams. Our machine can use three species for our experiments which at Rb87, K39, K40. Although as of yet we have only limited ourselves to the two bosonic species.
|Jonatan||Höschele||6||We present the design of a new experimental apparatus to realize subwavelength-spaced ordered arrays of ultracold strontium atoms. The apparatus consists of a high-vacuum part with a Zeeman slower and a 2D magneto-optical trap (MOT) to precool the atoms. A push beam then transports the atoms to the ultrahigh-vacuum chamber, where the atoms are captured and cooled in a 3D MOT. These first cooling stages are performed using the broad blue transition of strontium, at 461 nm. Subsequently, we transfer the atoms to a 3D MOT operating on the narrow red intercombination transition in order |
to further lower their temperature and load an optical dipole trap. Then we arrange the atoms in an array of deep optical traps, which are generated either by optical tweezers or by a deep optical lattice, operating at a magic wavelength.
In this lab-tour, we present the design of the machine and the current status of the experiment.