Alex successfully defended his PhD thesis!!

Alex did his PhD on our Cs quantum gas microscope.

Alex worked on our Cs quantum gas microscope. When he started there was no single-atom imaging in our group. One of the main challenges was the tiny lattice constant of only 383.5nm, which is extremely challenging to resolve even with a high-NA imaging objective with numerical aperture NA=0.8. His first main result was the development of an unsupervised machine learning algorithm for single-site reconstruction in this challenging regime, which enabled high-fidelity detection in this challenging regime (Commun. Phys. 2023)!

Moreover, using superlattice potentials, Alex and the Cs team implemented arbitrary measurements of nearest-neighbor orbital operators, which enables local measurements of currents in a quantum many-body system (Phys. Rev. Lett. 2024). Not only does this method offer unique possibilities for initial state preparation and read-out, it provides a path towards measurements of complex correlators via local z-rotations, which we can realized via our high-NA objective. 

The local current-measurement technique was finally applied to study strongly-interacting Meissner phases in optical ladders with artificial magnetic field (Nature Physics 2025). We managed to realize a low-temperature phase with ~24 strongly-interacting particles, marking a significant milestone for realizing large many-body systems in the presence of magnetic fields.

Thank you so much for all the hard work, for building such a great machine and for your dedication to make the flux ladder project go! It was a lot of fun working together!

Congratulations and all the best for your future! I am sure we’ll see a lot of great results very soon!