Recent results:
I.E. Mazets and G. Kurizki, Phys. Rev. Lett. 98, (2007).
We propose a new mechanism for tuning an atomic s-wave scattering length. The effect is caused by virtual transitions between different Zeeman sublevels via magnetic dipole-dipole interactions. These transitions give rise to an effective potential, which, in contrast to standard magnetic interactions, has an isotropic component and thus affects s-wave collisions.A. Mandilara, V.M. Akulin, M. Kolar and G. Kurizki, Phys. Rev. A 75, 22327(2007).
We propose a general formalism for analytical description of multiatomic ensembles interacting with a single-mode quantized cavity field under the assumption that most atoms remain unexcited on average. By combining the obtained formalism with the nilpotent technique for the description of multipartite entanglement we are able to overview in a unified fashion different probabilistic control scenarios of entanglement among atoms or examine atomic ensembles. We then apply the proposed control schemes to the creation of multiatom states useful for quantum information.G. Kurizki, I. E. Mazets, D. H. J. O'Dell, and W. P. Schleich, Int. J. Mod. Phys. B 18, 961-974 (2004).
We present a brief review of our recent results concerning non-mean-field effects of laser-induced dipole–dipole interactions on static and dynamical properties of atomic Bose–Einstein condensates.A. I. Artemiev, I. E. Mazets, G. Kurizki, and D. O'Dell, Int. J. Mod. Phys. B 18, 2027-2034 (2004).
We show that electromagnetically-induced isotropic dipole-dipole interactions in a spin-polarized non-degenerate fermionic gas can cause an extremely exothermic phase transition analogous to the isothermal collapse in gravitationally interacting star clusters. This collapse may result in fragmentation of the gas into a hot "halo" and a highly degenerate "core". Possible realization is envisaged in microwave-illuminated fermionic molecular gases at microkelvin temperatures.I. E. Mazets, D. H. J. O'Dell, G. Kurizki, N. Davidson, and W. P. Schleich, J. Phys. B 37, S155 (2004), cond-mat/0310672.
We study a gaseous Bose-Einstein condensate with laser-induced dipole-dipole using the Hartree-Fock-Bogoliubov theory within the Popov approximation. The dipolar interactions introduce long-range atom-atom correlations, which manifest themselves as increased depletion at momenta similar to that of the laser photon, as well as a "roton" dip in the excitation spectrum. Surprisingly, the roton dip and the corresponding peak in the depletion are enhanced by raising the temperature above absolute zero.M. Kalinski, I. E. Mazets, G. Kurizki, B. A Malomed, K. Vogel, and W. P. Schleich, cond-mat/0310480.
We present variational and numerical solutions of the generalized Gross--Pitaevskii equation for an atomic Bose--Einstein condensate with time-dependent, laser-induced dipole-dipole interactions (LIDDI). The formation of a supersolid ground state due to LIDDI in an elongated (cigar-shaped) BEC is investigated. It is found that the supersolid structure emerges if the laser intensity exceeds a critical value, which depends on the linear density of atoms in the BEC.D. O'Dell, S. Giovanazzi, G. Kurizki, . Mod. Opt., 50, 2655 (2003).
We consider a gaseous atomic Bose-Einstein condensate with dipole-dipole interactions induced by a far off-resonance laser. The long-range dipolar interactions introduce atom-atom correlations on the new scale of the laser wavelength, giving a controllable method of squeezing low energy modes. At high enough laser intensities the correlations lead to a roton minimum in the excitation spectrum.D. H. J. O'Dell, S. Giovanazzi and G. Kurizki, Phys. Rev. Lett. 90, 110402 (2003).
A gaseous Bose-Einstein condensate irradiated by a far off-resonance laser has long-range interatomic correlations caused by laser-induced dipole-dipole interactions. These correlations, which are tunable via the laser intensity and frequency, can produce a "roton" minimum in the excitation spectrum-behavior reminiscent of the strongly correlated superfluid liquid He II.S. Giovanazzi, D. O'Dell and G. Kurizki, Phys. Rev. Lett. 88, 130402 (2002).
We show that the dipole-dipole interatomic forces induced by an off-resonant running laser beam can lead to a self-bound pencil-shaped Bose condensate, even if the laser beam is a plane wave. For an appropriate laser intensity the ground state has a quasi-one-dimensional density modulation-a Bose-Einstein "supersolid".S. Giovanazzi, D. O'Dell, and G. Kurizki, Phys. Rev. A 63, 031603(R) (2001)
In our recent publication [D. O'Dell, et al, Phys. Rev. Lett. 84, 5687 (2000)] we proposed a scheme for electromagnetically generating a self-bound Bose-Einstein condensate with 1/r attractive interactions: the analog of a Bose star. Here we focus upon the conditions neccessary to observe the transition from external trapping to self-binding. This transition becomes manifest in a sharp reduction of the condensate radius and its dependence on the laser intensity rather than the trap potential.S. Giovanazzi, G. Kurizki, I. E. Mazets, and S. Stringari, Europhys. Lett. 56, 1 (2001); cond-mat/0101310
We investigate the collective excitations of an atomic Bose-Einstein condensate in the self-binding regime produced by electromagnetically induced "gravity" (1/r attraction). Analytical expressions for the frequencies of the monopole and quadrupole modes are obtained at zero temperature, using the sum-rule approach, and compared with the exact results available in the Thomas-Fermi limit. The low-energy dynamics of such condensates is shown to be dominated by the effective "plasma" frequency. An analog of the Jeans gravitational instability is analyzed.S. Giovanazzi, D. O'Dell and G. Kurizki, J. Phys. B 34, 4757 (2001);
We consider a trapped cigar-shaped atomic Bose-Einstein condensate irradiated by a single far-off resonance laser polarized along the cigar axis. The resulting laser induced dipole-dipole interactions between the atoms significantly change size of the condensate, and can even cause its self-trapping.D. O'Dell, S. Giovanazzi, G. Kurizki, and V. M. Akulin, Phys. Rev. Lett. 84, 5687 (2000).
We show that particular configurations of intense off-resonant laser beams can give rise to an attractive 1/r interatomic potential between atoms located well within the laser wavelength. Such a "gravitational-like" interaction is shown to give stable Bose-Einstein condensates that are self-bound (without an additional trap) with unique scaling properties and measurably distinct signatures.Commentary on the article: Why trapped atoms are
attractive,
by James Anglin, Nature (London) 406,
29 (2000);
Physicists
tell atoms to pull themselves together