Seminare

The universe has evolved from a far-from-equilibrium state post Big Bang. High-energy particle colliders stride to recreate such nonequilibrium conditions in experiment, to reach densities and temperatures necessary for generating some of the most short-lived states of matter, and to unravel equilibration and hadronization mechanisms. Theoretical studies of matter out of equilibrium, rooted in the fundamental gauge theories of nature, often require simulations that are intractable with classical computing. [mehr]

Narrow resonances corresponding to quantum transitions in atoms, molecules, quantum dots, rare-earth ions and color centers constitute the basis of quantum optics with numerous applications in sensing, imaging, computation, communication, etc. The highest quality atomic resonances have been achieved in atomic clocks. Their realization requires low atomic density, vacuum environment, laser cooling below 100 nK temperature, and magnetic traps or optical lattices. [mehr]

Our search for a quantum theory of gravity is aided by a unique and perplexing feature of the classical theory: General Relativity already knows about its own quantum states (the entropy of a black hole), and about those of all matter (via the covariant entropy bound). The results we are able to extract from classical gravity are inherently non-perturbative and increasingly sophisticated. Recent breakthroughs include a derivation of the entropy of Hawking radiation, a computation of the exact integer number of states of some black holes, and the construction of gravitational holograms in our universe using techniques from single-shot quantum communication protocols. [mehr]

The electric dipole moment of polar molecules and their rich internal structure makes them excellent candidates for applications in precision measurements, controlled ultracold chemistry, and quantum simulations. Many applications require that the molecular sample is cooled to limit the number of occupied quantum states and trapped. [mehr]

Abstract. We discuss the question of how can one treat the laser-induced (or laser-assisted)high-order processes of electrons (bound or free) nonperturbatively, in such a way that boththe electron-atom interaction and the quantized nature of radiation be simultaneously takeninto account? An analytic method is proposed to answer this question in the generalframework of nonrelativistic quantum electrodynamics. As an application, a quantum opticalgeneralization of the strong-field Kramers-Heisenberg formula has been derived fordescribing high-harmonic generation (HHG). [mehr]