Ultracold atoms in periodically modulated optical potentials: A quantum metamaterial to explore nonequilibrium dynamics and tosimulate relativistic effect

• Applicants: Professor Dr. Sergey Denisov, Ph.D.; Professor Dr. Martin Weitz
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 231556095

The main objective of this joint experiment-theory project is to study ac-driven ultracold atomic gases towards the goal of developing a new testing-ground for non-equilibrium quantum dynamics and relativistic physics effects. To reach this goal we will perform both theoretical studies, by using the quantum Floquet formalism and high-performance computing, and experiments with ultra-cold atomic gases in temporally modulated optical lattice potentials.The project is subdivided into two consecutive steps. Starting out we will focus on the non-equilibrium quantum regime of ac-driven optical lattice potentials. The specific questions we want to address are (i) transport resonances induced by avoided crossings between different Floquet states and (ii) uantum many-body effects on the atom transport in the limit of strong interparticle interactions and strong driving. The next step is to study ac-driven optical potentials as tunable quantum “metamaterials”. The key idea is to create Dirac cones in the quasienergy spectrum of a periodically-modulated quantum system through controllable avoided crossings between designated Floquet tates. To test the physics that follows from these Dirac cones we plan to carry out an experimental quantum simulation of relativistic Klein tunneling and also Veselago lensing with a cloud of ultracold atoms placed in driven optical potentials. Among possible applications of our anticipated outcomes are new Floquet-state based quantum tools, whose operational principles will rely on non-equilibrium physics and can be used to carry out quantum simulations of the relativistic manybody wave equation.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Peter Hänggi