We analyze the dynamics of a dilute, trapped Bose-condensed atomic gas coupled to a diatomic molecular Bose gas by coherent Raman transitions. This system is shown to result in a new type of “superchemistry,” in which giant collective oscillations between the atomic and the molecular gas can occur. The phenomenon is caused by stimulated emission of bosonic atoms or molecules into their condensa...

A round up of the present status of the conjecture that nα nuclei form an αparticle condensate in excited states close to the nα threshold is given. Experiments which could demonstrate the condensate character are proposed. Possible lines of further theoretical developments are discussed. In this article we want to report on the present status of our recent conjecture [1] that at least light nα...

We quantize the recent hydrodynamic analysis of Stringari for the low-energy collective modes of a trapped Bose gas at T = 0. This is based on the timedependent Gross-Pitaevskii equation, but omits the kinetic energy of the density fluctuations. We diagonalize the hydrodynamic Hamiltonian in terms of the normal modes associated with the amplitude and phase of the inhomogeneous Bose order parame...

We solve the Gross-Pitaevskii equations for a dilute atomic gas in a magnetic trap, modeled by an anisotropic harmonic potential. We evaluate the wave function and the energy of the Bose Einstein condensate as a function of the particle number, both for positive and negative scattering length. The results for the transverse and vertical size of the cloud of atoms, as well as for the kinetic and...

A Bose-Einstein condensate of atoms, trapped in an axially symmetric harmonic potential, is considered. By averaging the spatial density along the symmetry direction over a length that preserves the aspect ratio, the system may be mapped on to a zero temperature noninteracting Fermi-like gas. The “mock fermions” have a state occupancy factor (>> 1) proportional to the ratio of the coherance len...

In order to study non-zero spin excitations of the recently proposed αcluster condensation in the self-conjugate 4n nuclei, spatial deformation is introduced into the model wave function of the α-cluster condensate. The rotational band states of Be are investigated as a first step of a test case for the study of the deformation of the α-cluster condensate. Calculations reproduce well the bindin...

Spectacular experimental realizations of the BoseEinstein condensate ~BEC! in cooled and trapped atomic gases @1–3# stimulated intensive investigations of possible modifications, control, and manipulations of this new state of matter. Here a macroscopic sample of atoms is in a well defined quantum state. Thus several typically quantummechanical phenomena may now be investigated on a macroscopic...