August 2005

Schedule of Talks

Date/Time/Venue	Speaker	Topic
4 August 2005, Thursday, 4-5pm SOC1-07-14	Assoc. Prof Nicolas G. Hadjiconstantinou, MIT	Small-Scale Gaseous Hydrodynamics and the Breakdown of the Navier-Stokes Description
5 August 2005, Friday, 2:30-3:30pm SOC1-07-14	Dr. D. Jaksch, University of Oxford, UK	Modeling Cold Atoms in Optical Lattices

Small-Scale Gaseous Hydrodynamics and the Breakdown of the Navier-Stokes Description

Speaker: Assoc. Prof Nicolas G. Hadjiconstantinou

Date: 4 August 2005, Thursday, 4-5pm

Venue : CZ Seminar Room, SOC1-07-14

Abstract
The recent interest in systems and devices operating at small scales (MEMS, NEMS) has resulted in a need to expand our ability to model gaseous hydrodynamics at small scales. Of particular interest to us is a number of theoretical challenges which arise from the breakdown of the Navier-Stokes description when the characteristic flow length-scales approach the fluid internal scale (in this case the molecular mean free path). In this talk we will discuss recent progress in the theoretical modeling and simulation methods for small-scales gaseous flows in regimes where the Navier-Stokes description is expected to fail. On the simulation front we will present a recently developed simulation method for solving the Boltzmann equation which governs gaseous hydrodynamics beyond the Navier-Stokes description; the method presented here is significantly more computationally efficient compared to existing methods. On the flow-physics front we will discuss solutions to basic flow problems which extend our understanding of transport in gaseous systems beyond the Navier-Stokes limit. Both fluid flow and convective that transfer will be considered. Finally we will present a recently developed second-order slip model that extends the applicability of the Navier-Stokes description to length-scales approaching the mean free path scale. Such models are very desirable since analytical and numerical solutions of the Navier-Stokes description are significantly easier to obtain than solutions of the more general Boltzmann equation.

About the speaker
Dr Nicolas G. Hadjiconstantino is currently Associate professor at the Mechanical Engineering Dept., at MIT. His research focus is on multi-scale problems that require novel approaches in Computational fluid mechanics. He has worked on the development of hybrid algorithms matching molecular descriptions to continuum descriptions through domain decomposition or succesive refinement, or models that span a range of scales. Development of theoretical models of fluid behavior in situations where the continuum (Navier-Stokes) governing equations are not valid.

His Research Interests include the following fields: Computational Fluid Dynamics, Computational Statistical Mechanics, Hybrid Atomistic-Continuum methods, Interface Phenomena, Nanoscale Fluid Mechanics, Thermodynamics
More details related to Prof NGH can be found at the following URL. (http://www-me.mit.edu/people/personal/ngh.htm)

Modeling Cold Atoms in Optical Lattices

Speaker: Dr. D. Jaksch, University Lecturer, University of Oxford, UK

Date: 5 August 2005, Friday, 2:30-3:30pm

Venue: CZ Seminar Room, SOC1-07-14

Abstract
I will present recently developed tools for modeling ultra-cold atomic gases in optical lattices. These are described by Hubbard Hamiltonians and realize very clean strongly correlated systems with coherence times longer than the typical experimental time scale. For the first time they thus permit the study of unitary dynamics under well controlled conditions in strongly correlated systems, effectively at temperature T=0. Using newly developed simulation methods I will discuss the dynamics of quantum phase transitions from superfluid to Mott insulating states. Furthermore I will show how impurity atoms in optical lattices can be used as quantum switches for currents of neutral atoms. Finally I will present schemes for creating, detecting and characterizing multi partite entangled states in optical lattices.

About the speaker
Dr Jaksch obtained his Ph.D. from the University of Innsbruck. He is currently working at the Physics dept. University of Oxford. He works in Theoretical Physics with specialization in Quantum Optics, Bose-Einstein condensation, Quantum information etc. He has several publications in top journal such as PRL. More details on the reseach activities of the speaker can be obtained from the URL: (http://users.ox.ac.uk/~clar0085/ )