Laser system for Quantum Gas Microscopy of dynamical gauge fields with Yb atoms

• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452143298

Quantum Gas Microscopes for ultracold atoms in optical lattices have been remarkably successful in simulating important condensed matter models, in particular, by making use of the precise experimental control of the model parameters. In combination with gauge fields, more precisely dynamical gauge fields, the previously demonstrated experimental concepts could be generalized to simulate lattice gauge theories, which play an important role in describing many phenomena in quantum electrodynamics or high-energy physics. Lattice gauge theories require the realization of local symmetries, which up to know hinder successful implementations of such theories in large systems. With this experiment we plan to develop a novel lattice setup that offers a local control of tunnel couplings, which are the basis for a scheme to realize U(1) lattice gauge theories, where matter and gauge-field degrees of freedom can be implemented with a single fermionic species.The complete system consists of four main parts: 1) In order to achieve fast cycle times for quantum simulation, we plan to implement a fast and robust optical transport using a running-wave geometry. The potential will be realized with low-noise high-frequency lasers at 1064nm, which can also be used for optical dipole traps. Fast cycle times are essential for measurements of higher-order correlation functions, which require extremely high statistics. At the same time, short cycle times are beneficial, when it comes to minimizing unwanted drifts of fluctuations in the experiment and therefore offer a more reliable data taking. 2) The experimental technique for the local control of tunnel couplings is based on a special state-dependent lattice, which in addition will be used for single-site resolved imaging. To reach the required lattice depths we will use a Ti:Sa Lasersystem at 760nm. 3) To obtain detailed information about the internal-state and density distribution of the cold fermions in the lattice we plan to install a vertical superlattice at 1064nm and 532nm, which allows for an observation of the spin- and density distribution of the many-body state using topological spin pumping. 4) In order to control the frequency of the different lasers used for the state-dependent potentials, a wave meter with good absolute accuracy is needed. This allows us to stabilize the laser frequency and therefore keep the state-dependent potential constant for long times.The planned experimental setup will offer for the first time a local control of tunnel couplings in a large lattice systems. This is an ideal starting point for the implementation of local symmetries and hence lattice gauge theories. A successful realization of this scheme constitutes a unique opportunity to extend quantum simulations of many-body systems to other research areas, such as high-energy physics.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Lasersystem zur Quantengasmikroskopie für Yb Atome, rauscharme Hochleistungslaser und Diagnostik
• Instrumentation Group: 5700 Festkörper-Laser
• Applicant Institution: Ludwig-Maximilians-Universität München
• Leader: Professorin Dr. Monika Aidelsburger