Atomic Physics
Area Manager: Massimo Inguscio
A core research line at LENS concerns the study of ultracold quantum gases. By using suitable configurations of laser beams and magnetic fields it is possible to cool atomic gases down to few nanokelvin. At these ultra-low temperatures the atoms stop behaving as classical particles and their quantum nature emerges. If the particles are bosons they form a mesoscopic Bose-Einstein condensate (BEC), all collapsing into the same quantum state, while if they are fermions they form a Fermi-degenerate gas in which they completely fill all the lowest energy states available.
  • Cold atoms are the main ingredients of modern optical clocks, that can reach an accuracy of 10-18 seconds, against 10-15 s of atomic clocks. At LENS the research on optical clocks aims to simplify and reduce the size of the equipment to make them transportable, e.g. to send them in space. At lower temperatures, ultracold atoms in a condensed phase allow to perform atomic interferometry experiments and Strontium can be a useful quantum sensor to measure forces due to macroscopic source masses on micrometer distances, e.g. to investigate inverse-square Newton's law or Casimir effect.
  • Ultracold atoms trapped in optical lattices can be the material base for two kind of calculator: quantum computers and quantum simulators. In the first case, today's challenge at LENS concerns the ability to implement qubits, the basic elements of quantum information, on spin and/or electronic states of cold atoms (e.g. Itterbium) and to manipulate them one by one to perform calculations. In the second case, cold atoms in a optical lattices can show an electron-like behavior and allow an indirect study of conduction phenomena in condensed matter physics, such as superconductivity, Anderson localization, graphene properties and much more, thanks to the ability to draw very specific configurations of the lattices.
  • Interactions between atoms can be tuned by using static magnetic fields in proximity of so-called Feshbach resonances. The set of physical phenomena that can be studied by tuning intra- and inter-species interactions of atoms and mixtures in optical lattices is very large and ranges from the production of ultracold polar molecules to the engineering of novel quantum states of matter. The short-ranged isotropic interaction between atoms is indeed at the basis of superfluidity in Bose and Fermi systems, quantum phases in periodic and disordered potentials, entanglement. On the other hand, in a quantum gas of polar molecules a strong, tunable, long-range, anisotropic interaction appears, adding new ingredients to the study of superfluidity, quantum phase transitions, lattice models and quantum computation. Mixtures of different atoms that follow the two quantum statistics are also interesting to study a series of fundamental phenomena, ranging from condensed-matter to molecular physics.
  • Laser spectroscopy of cold molecules is a powerful tool to address fundamental physical questions. We develop new methods to cool and control neutral molecules and apply them to improve the resolution of the spectroscopic measurements. We develop novel narrow-linewidth light sources in the mid IR which are absolutely referenced to the primary frequency standard via a fibre-link to the National Metrological Institute in Torino, INRIM.