Synopsis: Entropy and order in optical lattices

Simulations address whether magnetic ordering is achievable with cold atoms in optical lattices.
Synopsis figure
Illustration: Sami Mitra

Can ultracold atoms in optical lattices be used as quantum simulators? Many groups are trying to answer this question by exploring regimes where the Hamiltonian of the system can be mapped onto either known or yet unexplored spin models. Among them, Ising antiferromagnetic (or checkerboard solid) and xy-ferromagnetic phases appear to work for two-component mixtures of bosons in optical lattices in two or three dimensions. The observation of magnetic ordering, however, requires rather low temperatures and entropies.

In a paper published in Physical Review A, Barbara Capogrosso-Sansone, Şebnem Söyler, Nikolay Prokof’ev, and Boris Svistunov—from the Harvard-Smithsonian Center of Astrophysics, the University of Massachusetts, both in the US, The Abdus Salam International Centre for Theoretical Physics, Italy, and also affiliated with the Kurchatov Institute in Russia—calculate the transition lines to magnetic phases by performing path integral Monte Carlo simulations. They discuss in detail how to get into regimes with favorable critical temperatures, what timescales are needed to observe the magnetic phases under typical experimental conditions, and how low the entropy needs to be in order to achieve the predicted quantum states. Their work is expected to provide good guidance and benchmarking for ongoing experiments to create optical lattice emulators, where the low temperature and entropy present substantial challenges. – Franco Dalfovo


More Announcements »

Subject Areas

Atomic and Molecular PhysicsOptics

Previous Synopsis

Next Synopsis

Related Articles

Viewpoint: Cavity with Iron Nuclei Slows Down X Rays

Viewpoint: Cavity with Iron Nuclei Slows Down X Rays

Slow light effects have been measured for x rays using a cavity filled with iron nuclei, where the speed of light was reduced by a factor of 10,000. Read More »

Synopsis: Dipolar Gas Chilled to Near Zero
Atomic and Molecular Physics

Synopsis: Dipolar Gas Chilled to Near Zero

The cooling of strongly dipolar molecules to their absolute ground state has opened the possibility of creating new forms of matter. Read More »

Synopsis: Nanofiber Optical Memory
Quantum Information

Synopsis: Nanofiber Optical Memory

Light signals propagating down an ultrathin fiber can be temporarily stored in a cloud of cold atoms surrounding the fiber. Read More »

More Articles