tag:www.physik.uni-hamburg.de,2005:/en/iqp/sengstock/research/lithium-microscope/newsNews from the Lab2023-08-25T12:39:18ZNAGR-fakmin-27145716-production2021-08-12T16:00:00ZFloquet engineering of quantum gases<img width="293" height="165" style="float:left" src="https://assets.rrz.uni-hamburg.de/instance_assets/fakmin/27145904/figure-floquet-engineering-en-733x414-936e4c0b7e5737b0166a8268cc8643ec08920eec.jpg" /><p>In a new review article in Nature Physics, Christof Weitenberg and Juliette Simonet from the ILP give a current overview and a basic introduction to the field of Floquet enginnering of quantum gases with a focus on ultracold atoms in optical lattices, to which leading contributions came from the ILP.</p>
<p>Nature Physics (2021), DOI:10.1038/s41567-021-01316-x</p>
<p>CUI Press Release</p><p>Photo: UHH/Weitenberg, Simonet</p>NAGR-fakmin-26117939-production2020-09-17T22:00:00ZPreparation of the 1/2-Laughlin state with atoms in a rotating trap<img width="293" height="165" style="float:left" src="https://assets.rrz.uni-hamburg.de/instance_assets/fakmin/26117902/andrade2020-733x414-3ea231871341ffc8661eea1b0d91783e3a171267.jpg" /><p>Fractional quantum Hall systems are among the most exciting strongly correlated systems. Accessing them microscopically via quantum simulations with ultracold atoms would be an important achievement toward a better understanding of this strongly correlated state of matter. A promising approach is to confine a small number of bosonic atoms in a quasi-two-dimensional rotating trap, which mimics the magnetic field. For rotation frequencies close to the in-plane trapping frequency, the ground state is predicted to be a bosonic analog of the Laughlin state.</p>
<p>In this collaboration with ICFO Barcelona, we numerically study the problem of the adiabatic preparation of the Laughlin state by ramping the rotation frequency and controlling the ellipticity of the trapping potential. By employing adapted ramping speeds for rotation frequency and ellipticity, and large trap deformations, we improve the preparation time for high-fidelity Laughlin states by a factor of ten in comparison to previous studies. With this improvement of the adiabatic protocol the Laughlin state can be prepared with current experimental technology.</p>
<p>B. Andrade et al., Phys. Rev. A 103, 063325 (2021)</p><p>Photo: Adapted from PRA 103, 063325 (2021)</p>NAGR-fakmin-18134653-production2018-07-26T22:00:00ZERC starting grant "Engineering and probing anyonic quantum gases" for Christof<img width="293" height="165" style="float:left" src="https://assets.rrz.uni-hamburg.de/instance_assets/fakmin/18136892/erc-starting-grant733x414-27e634940fadeecfa2eb3a4aab1732996cb00ece.png" /><p>Using the quantum gas microscope, we will study fractional quantum Hall states in rotating microtraps and the anyonic quasiparticles that emerge in the strongly correlated regime.</p><p>Photo: Christof Weitenberg</p>NAGR-fakmin-18134666-production2018-06-22T22:00:00ZQuantum point spread function for imaging trapped few-body systems with a quantum gas microscope<img width="293" height="165" style="float:left" src="https://assets.rrz.uni-hamburg.de/instance_assets/fakmin/26118114/pyzh2019-733x414-348c95e4ee50d934c227e746176ec495a5912911.jpg" /><p>In collaboration with Maxim Pyzh, Sven Krönke and Peter Schmelcher, we have worked out a protocol for the imaging of trapped few-body systems with a quantum gas microscope and introduced the concept of a quantum point spread function. Quantum gas microscopes, which image the atomic occupations in an optical lattice, have opened a new avenue to the exploration of many-body lattice systems. Imaging trapped systems after freezing the density distribution by ramping up a pinning lattice leads, however, to a distortion of the original density distribution, especially when its structures are on the scale of the pinning lattice spacing. We show that this dynamics can be described by a filter, which we call in analogy to classical optics a quantum point spread function. Using a machine learning approach, we demonstrate via several experimentally relevant setups that a suitable deconvolution allows for the reconstruction of the original density distribution. These findings are both of fundamental interest for the theory of imaging and of immediate importance for current quantum gas experiments.</p>
<p>New J. Phys. 21, 053013 (2019)</p><p>Photo: M. Pyzh, taken from New J. Phys. 21, 053013 (2019)</p>NAGR-fakmin-18134680-production2018-04-24T22:00:00ZThe high-resolution objective is installed<img width="293" height="165" style="float:left" src="https://assets.rrz.uni-hamburg.de/instance_assets/fakmin/18136912/vacuum-chamber733x414-778ff8b943427340f973ed5ae2de60156e39d442.jpg" /><p>The high-resolution objective is installed underneath the glass cell. It was previously tested separately and found to reach the resolution of 800 nm at 671 nm wavelength.</p><p>Photo: AG Sengstock</p>