Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.

The organizing committee includes Malcolm Boshier (P-21), Adolfo del Campo (T-4 & CNLS), Michael Di Rosa (C-PCS), Armin Rahmanisisan (T-4 & CNLS), Changhyun Ryu (P-21) , Nikolai Sinitsyn (T-4), Rolando Somma (T-4), Christopher Ticknor (T-1), and Wojciech Zurek (T-4).

For more information, or to nominate a speaker, contact Adolfo del Campo.

To add your name to the Quantum Lunch email list, contact Ellie Vigil.

Thursday February 6, 2014
12:30 PM - 2:00 PM

Speaker: Riccardo Rota (Trento)

Technical Host: Eddy Timmermans

TOPIC: Dynamic properties of hard-sphere Bose systems: from ultracold gases to superfluid helium

Abstract
Using quantum Monte Carlo methods, we perform zero-temperature calculations of the dynamic structure factor of a system of Bose particles interacting via a hard-sphere potential. The hard-sphere model is able to capture, in the dilute regime, the essential properties of ultracold atoms with positive scattering length, and, at higher densities, it can been used to characterize strongly interacting systems where the hard-core repulsion at short distances is the leading part of the interatomic potential, like superfluid helium.
With increasing density, we observe the appearance of an incoherent, multiphonon contribution in the spectral function at frequencies higher than the single quasi-particle peak and a crossover of the dispersion of elementary excitations from a Bogoliubov-like spectrum to a phonon-maxon-roton curve. The behavior of the dynamic structure factor at the same density in the stable solid and metastable gas phase above the freezing point is also discussed.