JQI Special Seminar

Abstract: Quantum simulations of complex materials address fundamental problems that cannot be analytically solved due to the exponential scaling of the Hilbert space with increasing particle number. Simulations using trapped ions have had remarkable success investigating one-dimensional quantum interacting spin models, and we seek to extend these ideas to two dimensions by exploiting new crystal geometries in a rf Paul trap.

Abstract:  The Fermi-Hubbard model (FHM) describes the interplay between kinetic energy and onsite interaction of particles on a lattice. Cold atoms in an optical lattice have proven to be a particularly suitable platform to probe its properties, complementing analytical and numerical simulations. Most of the experimental works, however, have focussed so far on the SU(2) case, featuring spin-1/2 particles. In our experiment, we implement the SU(N) FHM, which describes particles with N spin components and presents a richer and still poorly understood physics compared with the SU(2) case.

Abstract: We experimentally study the many-body out-of-equilibrium dynamics of a three-dimensional, dipolar-interacting spin system with tunable XYZ Heisenberg anisotropy. We utilize advanced Hamiltonian engineering techniques and leverage the inherent disorder in the system to probe global and local spin autocorrelation functions for various XYZ Hamiltonians.

Abstract: Our experimental projects at the Laser Physics Institute (North Paris University) aim at characterizing entanglement for many-body systems made of large spin atoms. For this, we developed two experimental set-ups : one with large-spin strontium fermionic atoms, with spin-independent contact interactions; one with large-spin chromium bosonic atoms, with spin-dependent long-range dipole-dipole interactions.
 

Abstract: In this talk I will describe our recent theoretical work showing how several problems in atomic superfluid rotation can be addressed  using the versatile toolbox of cavity optomechanics [1]. We consider an annular Bose-Einstein condensate, which exhibits dissipationless flow and is a paradigm of rotational quantum physics, inside a cavity excited by optical fields carrying orbital angular momentum.

Abstract: Can a material be made of light? Can quantum mechanics help us measure time? These are two questions in quantum science that I directly address using the tools of atomic physics and quantum optics. We first explore the requirements to make a quantum Hall material made of light. We trap photons inside of a curved-mirror non-planar optical resonator to confine the transverse motion of photons and imbue them with an effective mass and an effective magnetic field for photons.

Recently, there has been remarkable progress towards the development of large-scale quantum devices through advances in quantum science and technology. This progress opens new doors for proof-of-principle demonstrations of quantum simulations as well as practically useful applications, such as quantum-enhanced metrology and quantum networking.

Artificial materials made up of atoms, molecules, and light have opened up exciting opportunities to explore quantum physics in exotic regimes. Through their manipulation with laser light and other fields, ultracold gases of atoms and molecules can be used to study phenomena related to condensed matter, high energy, and nuclear physics, and can furthermore play host to entirely unique kinds of many-body effects.

Learning how to create, study, and manipulate highly entangled states of matter is key to understanding exotic phenomena in condensed matter and high energy physics, as well as to the development of useful quantum computers. In this talk, I will discuss recent experiments where we demonstrated the realization of a quantum spin liquid phase using Rydberg atoms on frustrated lattices and a new architecture based on the coherent transport of entangled atoms through a 2D array.