Nonlinear properties of Bose Einstein condensates PostDoc Position on

Nonlinear properties of Bose Einstein condensates Nonlinear properties of Bose Einstein condensates

The observation of Bose-Einstein condensation (BEC) in magnetically trapped atomic vapours of rubidium, sodium, and lithium has opened a new field of study involving both atomic and condensed matter physics. At present, Bose-Einstein condensates are produced routinely in many laboratories (in Italy in Pisa and Florence) which enable researchers to study both experimentally and theoretically condensate properties such as nonlinear effects arising from inter-particle interactions, collective excitations, interactions between adjacent condensates, etc. In real experiments of BEC, atoms are trapped in three-dimensional (generally anisotropic) external potentials created by a magnetic trap and their collective dynamics can be described, in the mean field approximation, by the well known Gross-Pitaevskii equation. This equation, besides a confining potential (usually of parabolic type), contains a nonlinear interaction term which in first approximation is proportional to the s-wave scattering length characterizing the two-body interaction among the athoms. It is of great interest that this fundamental equation of motion for the condensate take the form of a nonlinear Schroedinger equation (NLS) which, for the past 30 years, has been the subject of intense ivestigations (also in our group) both in the area of mathematical-physics and nonlinear science (nonlinear optics). In particular, properties of the solitary wave solutions (bright and dark solitons) and of the collapsing solutions (blowing-up) have been deeply investigated. Such results, obtained in areas apparentely far from the physics community presently working on BEC, enphasize the interdisciplinary character of the reserch and the necessity of working in teams with different competences.

The PostDoc position will deal with investigations of non linear properties of trapped Bose-Einstein condensates in the the presence of external periodic field. In particular, the problem of the Bloch Oscillations of BEC condensates with positive and negative scattering length, is expected to be investigated in the framework of the nonlinear Schroedinger equation for the lowest energy eigenfunction.

Experience with the semiclassical and quantum aspects of the problem, as well as with perturbative and numerical studies of nonlinear equations (continuous and discrete NLS), in presence of external fields, is required.

The position is for one year. The starting is 1 June 2001 and the salary is 2ML (net) per month. Health insurance is covered and access to research money is possible.

Interestead candidates should send by March 31 2001, their CV with a complete publication list (in ps or pdf), to: