Properties Of Bose-Einstein Condensate Research Articles

Interface of Two-component Bose-Einstein Condensates in Double-parabola Approximation

In this work we proposed a simple method to determine the coordinate of interface of two-component Bose-Einstein condensates (BECs) in double parabola approximation (DPA). Based on this idea, the static properties of BECs have been investigated totally in DPA

Axions: From magnetars and neutron star mergers to beam dumps and BECs

We review topics in searches for axion-like-particles (ALPs), covering material that is complementary to other recent reviews. The first half of our review covers ALPs in the extreme environments of neutron star cores, the magnetospheres of highly magnetized neutron stars (magnetars), and in neutron star mergers. The focus is on possible signals of ALPs in the photon spectrum of neutron stars and gravitational wave/electromagnetic signals from neutron star mergers. We then review recent developments in laboratory-produced ALP searches, focusing mainly on accelerator-based facilities including beam-dump type experiments and collider experiments. We provide a general-purpose discussion of the ALP search pipeline from production to detection, in steps, and our discussion is straightforwardly applicable to most beam-dump type and reactor experiments. We end with a selective look at the rapidly developing field of ultralight dark matter, specifically the formation of Bose–Einstein Condensates (BECs). We review the properties of BECs of ultralight dark matter and bridge these properties with developments in numerical simulations, and ultimately with their impact on experimental searches.

Optomechanical effects in superfluid properties of BEC in an optical lattice

AbstractWe investigate the effects of a movable mirror (cantilever) of an optical cavity on the superfluid properties and the Mott phase boundary of a Bose-Einstein condensate (BEC) in an optical lattice. The Bloch energy, effective mass, Bogoliubov energy and the superfluid fraction are modified due to the mirror motion. The mirror motion is also found to modify the Mott-superfluid phase boundaries. This study reveals that the mirror emerges as a new handle to coherently control the superfluid properties of the BEC.

Bose–Einstein condensates with spatially inhomogeneous interaction and bright solitons

In this Letter, we investigate the dynamics of Bose–Einstein Condensates (BECs) with spatially inhomogeneous interaction and generate bright solitons for the condensates by solving the associated mean field description governed by the Gross–Pitaevskii (GP) equation. We then investigate the properties of BECs in an optical lattice and periodic potential. We show that the GP equation in an optical lattice potential is integrable provided the interaction strength between the atoms varies periodically in space. The model discussed in the Letter offers the luxury of choosing the form of the lattice without destroying the integrability. Besides, we have also brought out the possible ramifications of the integrable model in the condensates of quasi-particles.

Analytic Study of a Bose–Einstein Condensate in Waveguide with an Obstacle Potential

We investigate the exact solutions of one-dimensional (1D) time-independent Gross–Pitaevskii equation (GPE), which governs a Bose–Einstein condensate (BEC) in the magnetic waveguide with a square-Sech potential. Both the bound state and transmission state are found and the corresponding spatial configurations and transport properties of BEC are analyzed. It is shown that the well-known absolute transmission of the linear system can occur in the considered nonlinear system.

From squeezed atom lasers to teleportation of massive articles

The development of the Raman atom laser promises to make available new techniques for accessing and manipulating the quantum statistical properties of Bose-Einstein condensates. In this work we show how, combined with the already existing methods for the manipulation of quantum states of light which are central to quantum optics, the Raman input-output coupling mechanisms potentially enable the production of quadrature squeezed and sub-Poissonian atomic beams, and entanglement between atomic and optical fields. We also propose a method of measuring the quantum statistics of the atomic beam by transferring them to an optical field. Finally, by combning these techniques, we propose a method of teleporting the atom laser beam from one trapped condensate to another.

Early Universe Quantum Processes in BEC Collapse Experiments

We show that in the collapse of a Bose–Einstein condensate (BEC)4certain processes involved and mechanisms at work share a common origin with corresponding quantum field processes in the early universe such as particle creation, structure formation, and spinodal instability. Phenomena associated with the controlled BEC collapse observed in the experiment of Donley et al. (Donley, E., et al. (2001), Nature 412, 295; Claussen, N. (2003), PhD Thesis, University of Colorado; Claussen, N., et al. (2003), Physical Review A 67, 060701(R))(they call it “Bose–Nova,” see also Chin, J., Vogels, J., and Ketterle, W. (2003), Physical Review Letters 90, 160405) such as the appearance of bursts and jets can be explained as a consequence of the squeezing and amplification of quantum fluctuations above the condensate by the dynamics of the condensate. Using the physical insight gained in depicting these cosmological processes, our analysis of the changing amplitude and particle contents of quantum excitations in these BEC dynamics provides excellent quantitative fits with the experimental data on the scaling behavior of the collapse time and the amount of particles emitted in the jets. Because of the coherence properties of BEC and the high degree of control and measurement precision in atomic and optical systems, we see great potential in the design of tabletop experiments for testing out general ideas and specific (quantum field) processes in the early universe, thus opening up the possibility for implementing “laboratory cosmology.”

Phase fluctuations in Bose–Einstein condensates

We demonstrate the existence of phase fluctuations in elongated Bose-Einstein Condensates (BECs) and study the dependence of those fluctuations on the system parameters. A strong dependence on temperature, atom number, and trapping geometry is observed. Phase fluctuations directly affect the coherence properties of BECs. In particular, we observe instances where the phase coherence length is significantly smaller than the condensate size. Our method of detecting phase fluctuations is based on their transformation into density modulations after ballistic expansion. An analytic theory describing this transformation is developed.

Probing the statistical properties of Bose-Einstein condensates with light

A scattering of short, weak, nonresonant laser pulses on a Bose-Einstein condensate is proposed as a tool for studying its statistical properties. We show in particular that the variance of the number of scattered photons may distinguish between the Poisson and microcanonical statistics.