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 wavelength. Such a ``gravitational-like'' interaction is shown stable Bose-Einstein condensates are self-bound (without additional trap) with unique scaling properties and measurably distinct signatures.

A gaseous Bose-Einstein condensate irradiated by a far off-resonance laser has long-range interatomic correlations caused laser-induced dipole-dipole interactions. These correlations, which are tunable via the intensity and frequency, can produce "roton" minimum in excitation spectrum--behavior reminiscent of strongly correlated superfluid liquid He II.

We present exact results in the Thomas-Fermi regime for statics and dynamics of a harmonically trapped Bose-Einstein condensate that has dipole-dipole interactions addition to usual $s$-wave contact interactions. Remarkably, despite nonlocal anisotropic nature dipolar interactions, density profile general time-dependent harmonic trap is an inverted parabola. The evolution radii governed by local, ordinary differential equations, as example we calculate monopole quadrupole shape oscillation...

We derive an exact solution to the Thomas-Fermi equation for a Bose-Einstein condensate which has dipole-dipole interactions as well usual s-wave contact interaction, in harmonic trap. Remarkably, despite non-local anisotropic nature of dipolar interaction is inverted parabola, pure case, but with different aspect ratio. Various properties such electrostriction and stability are discussed.

A medium described by an imaginary potential (or (refractive index)), that varies sinusoidally in one direction, acts as a volume grating for plane waves incident on it obliquely or normally. Two peculiar features are identified. First, if the is weak, so there only two significant diffracted beams near Bragg angle, and three normal incidence, diffraction strongly affected degeneracies of non-Hermitian matrix generating `Bloch waves' grating; effect these very different from Hermitian...

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 is plane wave. For appropriate intensity ground state has quasi-one-dimensional density modulation---a Bose-Einstein ``supersolid.''

We investigate the collapse of a trapped dipolar Bose-Einstein condensate. This is performed by numerical simulations Gross-Pitaevskii equation and novel application Thomas-Fermi hydrodynamic equations to collapse. observe regimes both global collapse, where system evolves highly elongated or flattened state depending on sign interaction, local which arises due dynamically unstable phonon modes leads periodic arrangement density shells, disks, stripes. In adiabatic regime, ground states are...

We perform a theoretical study into how dipole-dipole interactions modify the properties of superfluid vortices within context two-dimensional atomic Bose gas co-oriented dipoles. The reduced density at vortex acts like giant anti-dipole, changing profile and generating an effective dipolar potential centred core whose most slowly decaying terms go as $1/\rho^2$ $\ln(\rho)/\rho^3$. These effects vortex-vortex interaction which, in particular, becomes anisotropic for dipoles polarized plane....

We calculate the critical rotation frequency at which a vortex state becomes energetically favorable over vortex-free ground in harmonically trapped Bose-Einstein condensate whose atoms have dipole-dipole interactions as well usual $s$-wave contact interactions. In Thomas-Fermi (hydrodynamic) regime, dipolar condensates oblate cylindrical traps (with dipoles aligned along axis of symmetry trap) tend to lower frequencies than their purely interaction counterparts. The converse is true for...

We describe a new class of nonequilibrium quantum many-body phenomena in the form networks caustics that dominate wave function semiclassical regime following sudden quench. It includes light cone-like propagation correlations as particular case. Caustics are singularities formed by birth and death waves hierarchy universal patterns whose natural mathematical description is via catastrophe theory. Examples classical range from rainbows gravitational lensing optics to tidal bores rogue...

We analyze the hydrodynamic solutions for a dilute Bose-Einstein condensate with long-range dipolar interactions in rotating, elliptical harmonic trap. The static and their regimes of dynamical instability vary nontrivially strength interactions. comprehensively map out this behavior, and, particular, examine experimental routes toward unstable dynamics, which, analogy to conventional condensates, may lead vortex lattice formation.

We derive the criteria for Thomas-Fermi regime of a dipolar Bose-Einstein condensate in cigar-shaped, pancake-shaped, and spherical geometries. These also naturally gives mean-field one- two-dimensional regimes. Our predictions, including analytic forms density profiles, are shown to be excellent agreement with numerical solutions. Importantly, anisotropy interactions has profound effect on low-dimensional criteria.

We present a general method for obtaining the exact static solutions and collective excitation frequencies of trapped Bose-Einstein condensate (BEC) with dipolar atomic interactions in Thomas-Fermi regime. The incorporates analytic expressions potential an arbitrary polynomial density profile, thereby reducing problem handling non-local to solution algebraic equations. comprehensively map out modes, including non-cylindrically symmetric traps, also case negative scattering length where...

We study the family of static and moving dark solitons in quasi-one-dimensional dipolar Bose-Einstein condensates, exploring their modified form interactions. The density dip soliton acts as a giant anti-dipole which adds non-local contribution to conventional local soliton-soliton interaction. map out stability diagram function strength polarization direction atomic dipoles, identifying both roton phonon instabilities. Away from these instabilities, collide elastically. Varying relative...

We study the stability, form and interaction of single multiple dark solitons in quasi-one-dimensional dipolar Bose-Einstein condensates. The are found numerically as stationary solutions moving frame a non-local Gross Pitaevskii equation, characterized function key experimental parameters, namely ratio atomic interactions to van der Waals interactions, polarization angle condensate width. their integrals motion strongly affected by phonon roton instabilities system. Dipolar matter-wave...

We present a theoretical analysis of dilute gas Bose-Einstein condensates with dipolar atomic interactions under rotation in elliptical traps. Working the Thomas-Fermi limit, we employ classical hydrodynamic equations to first derive rotating condensate solutions and then consider their response perturbations. thereby map out regimes stability instability for and, latter case, discuss possibility vortex lattice formation. our results propose several routes induce formation condensate.

The experimental realization of quantum-degenerate Bose gases made atoms with sizeable magnetic dipole moments has created a new type fluid, known as quantum ferrofluid, which combines the extraordinary properties superfluidity and ferrofluidity. A hallmark superfluids is that they are constrained to rotate through vortices quantized circulation. In ferrofluids long-range dipolar interactions add ingredients by inducing magnetostriction instabilities, also affect structural vortex lattices....

We study a model describing $N$ identical bosonic atoms trapped in double-well potential together with single-impurity atom, comparing and contrasting it throughout the Dicke model. As boson-impurity coupling strength is varied, there symmetry-breaking pitchfork bifurcation which analogous to quantum phase transition occurring Through stability analysis around point, we show that critical value of has same dependence on parameters as also that, like model, mean-field dynamics goes from being...

In this paper we show how the quantum mechanics of inverted harmonic oscillator can be mapped to a particle in super-critical inverse square potential. We demonstrate by relating both these systems Berry-Keating system with hamiltonian $H=(xp+px)/2$. It has long been appreciated that potential an ambiguity choosing boundary condition near origin and is system. Imposing requires specifying distance scale where it applied changes come renormalization group (RG) evolution ensures observables do...

In our recent publication [D. O'Dell et al., Phys. Rev. Lett. 84, 5687 (2000)] we proposed a scheme for electromagnetically generating self-bound Bose-Einstein condensate with $1/r$ attractive interactions: the analog of Bose star. Here focus upon conditions necessary to observe transition from external trapping self-binding. This becomes manifest in sharp reduction radius and its dependence on laser intensity rather than trap potential.

We investigate the time taken for global collapse by a dipolar Bose-Einstein condensate. Two semianalytical approaches and exact numerical integration of mean-field dynamics are considered. The based on Gaussian ansatz Thomas-Fermi solution shape regimes validity these two determined, their predictions revealed compared with simulations. interactions introduce anisotropy into predominantly lead to in plane perpendicular axis polarization.

Cold atoms in an optical lattice execute Bloch-Zener oscillations when they are accelerated. We have performed a theoretical investigation into the case is intra-cavity field of driven Fabry-Perot resonator. When oscillate inside resonator, we find that their back-action modulates phase and intensity light transmitted through cavity. solve coupled atom-light equations self-consistently show that, remarkably, Bloch period unaffected by this back-action. The provides way to observe oscillation...

The authors demonstrate that the light cones which spread information in spin chains are examples of quantum caustics, i.e. versions a class phenomena includes ship's wakes and rainbows. Caustics form hierarchy, described by catastrophe theory, gives natural explanation emergence universal scaling wave functions dressing cones: simplest is Airy function while more general situations lead to Pearcey Hyperbolic Umbilic functions. presence space-time vortices inside also predicted.

We calculate the band structure of ultracold atoms located inside a laser-driven optical cavity. For parameters where atom-cavity system exhibits bistability, atomic develops loop structures akin to ones predicted for Bose-Einstein condensates in ordinary (non-cavity) lattices. However, our case nonlinearity derives from cavity back-action rather than direct interatomic interactions. find both bi- and tri-stable regimes associated with lowest band, show that multistability we observe can be...

We study rainbow (fold) and cusp catastrophes that form in Fock space following a quench Bose Josephson junction. In the Gross-Pitaevskii mean-field theory, rainbows are singular caustics, but second-quantized theory Poisson resummation of wave function shows they described by well-behaved Airy functions. The structural stability these caustics against variations initial conditions Hamiltonian evolution is guaranteed catastrophe theory. also show long-time dynamics ergodic. Our results...