Skip to main content

Exploring lattice gauge theories with fermionic Ytterbium atoms

Periodic Reporting for period 2 - LaGaTYb (Exploring lattice gauge theories with fermionic Ytterbium atoms)

Reporting period: 2020-08-01 to 2022-01-31

Our project aims at performing quantum simulation experiments with ultracold fermionic atoms in optical lattices, which will allow us to study phenomena related to high-energy physics using table-top experiments. Quantum effects play a large role in many areas of physics, ranging from condensed matter to particle physics. Unfortunately, understanding the complex interplay between many interacting quantum particles is generally beyond what can be computed using state-of-the-art numerical techniques. In order to gain additional insights the complexity of the problem is typically reduced by identifying the main microscopic features of the system, which are responsible for the observed phenomena. A good example is the so-called Fermi-Hubbard model – a famous condensed-matter model, that has only two main parameters: tunneling or motion of fermions in a periodic potential and on-site interactions between them. However, despite having only two parameters the model is too complex to be solved exactly. This underlines the complexity of quantum many-body systems and the challenges we face, when trying to understand them. On the other hand, this also highlights their unique potential for future technological applications. Quantum simulation offers an alternative approach to solve complex many-body problems. The idea goes back to Richard Feynman, who proposed to use a well-controlled quantum mechanical system to simulate the behavior of interest. In our experiments we build such devices using ultracold atoms in optical lattices. The main apparatus consists of a vacuum chamber in which the atoms are cooled and trapped using laser beams. In the final configuration the interfering laser beams form a crystal-like array of potential minima, where the atoms are trapped and between which they can tunnel in order to move in the lattice. This resembles the motion of electrons in an ion crystal and allows us to study fundamental phenomena in condensed matter and statistical physics. Within this project we are trying to go beyond that and establish a new platform that combines periodic optical lattices with precise local control in order to access more exotic phenomena from high-energy physics.
We have successfully finished setting up the main infrastructure and the main experimental setup. As a next step we will cool the Yb atoms using laser beams and trap them into optical lattices. In parallel, we are working on the local control, which is a key ingredient for the proposed quantum simulation scheme.
We are developing a novel approach which will enable extremely fast cycle times for quantum simulation experiments combined with unprecedented control over local tunnelings, which can even be controlled in a state-dependent manner. This technique is based on the optical clock transition available in Yb atoms. We anticipate that after the successful completion of the experimental apparatus, novel entangling gates and high-fidelity large-scale quantum simulation of lattice gauge theories will be possible. This is a stepping stone towards studying phenomena related to high-energy physics using table-top experiments.
Schematic illustration of ultracold atoms in optical lattices with local control