Related papers: Reduction and Emergence in Bose-Einstein Condensat…
In the absence of losses the phase of a Bose-Einstein condensate undergoes collapses and revivals in time due to elastic atomic interactions. As experiments necessarily involve inelastic collisions, we develop a model to describe the phase…
A dynamical correspondence is established between positively curved, isotropic, perfect fluid cosmologies and quasi-two-dimensional, harmonically trapped Bose-Einstein condensates by mapping the equations of motion for both systems onto the…
In this paper, we mainly review recent results on mathematical theory and numerical methods for Bose-Einstein condensation (BEC), based on the Gross-Pitaevskii equation (GPE). Starting from the simplest case with one-component BEC of the…
We prove two equilibrium properties of a system of interacting atoms in three or higher dimensional continuous space. (i) If the particles interact via pair potentials of a nonnegative Fourier transform, their self-organization into…
A unique feature of multi-component BECs is the possibility of beating frequencies in collective oscillations. We analytically determine this beating frequency for the two-component BEC in one-dimension. We also show that the Thomas-Fermi…
In these lectures we discuss condensates which are formed in quark matter when it is squeezed and in a gas of fermionic atoms when it is cooled. The behavior of these two seemingly very different systems reveals striking similarities. In…
We aim here to show that reductionism and emergence play a complementary role in understanding natural processes and in the dynamics of science explanation. In particular, we will show that the renormalization group - one of the most…
This paper argues that the physics of condensed matter cannot be fully reduced to the supposedly fundamental quantum mechanical theory for all the atoms of which the system consists. In fact, there are many reasons to reject the idea that…
The realisation of Bose-Einstein condensation under grand-canonical conditions has provided the experimental evidence for the simultaneous occurrence of macroscopic fluctuations and phase coherence of the condensate. The observation of…
Recent conjectures that there are mesoscopically ``large'' extra dimensions, through which gravity propagates have interesting implications for much of physics. The scenario implies gross departures from Newton's law of gravity at small…
We present the experimental discovery of compound structures comprising solitons and vortex rings in Bose-Einstein condensates (BECs). We examine both their creation via soliton-vortex collisions and their subsequent development, which is…
We investigate the possibility that the BEC-like phenomena recently detected on two-dimensional finite trapped systems consist of fragmented condensates. We derive and diagonalize the one-body density matrix of a two-dimensional…
The properties of systems with Bose-Einstein condensate in external time-independent random potentials are investigated in the frame of a self-consistent stochastic mean-field approximation. General considerations are presented, which are…
The transition from the quantum to the classical world and its relation to Bose-Einstein condensation and superfluidity is explained in ten equations.
We have observed Bose-Einstein condensation of an atomic gas in the (quasi-)uniform three-dimensional potential of an optical box trap. Condensation is seen in the bimodal momentum distribution and the anisotropic time-of-flight expansion…
We perform the theoretical study on the unconventional Bose-Einstein condensations (UBEC) in the high bands of optical lattices observed by Hemmerich's group. These exotic states are characterized by complex-valued condensate wavefunctions…
We study the energies and decay of elementary excitations in weakly interacting Bose-Einstein condensates within a finite-temperature gapless second-order theory. The energy shifts for the high-lying collective modes turn out to be…
The Bose-Einstein condensation (BEC) of photons has been realized in one- and two-dimensional systems. When considering the influence of finite-size effect, the condensation in the one-dimensional fibre is of special interest since such a…
Exciton condensation, the Bose-Einstein-like condensation of quasibosonic particle-hole pairs, has been the subject of much theoretical and experimental interest and holds promise for ultra-energy-efficient technologies. Recent advances in…
We discuss the possibility that dark matter axions form a Bose-Einstein condensate (BEC) due to the gravitational self-interactions. The formation of BEC occurs in the condensed regime, where the transition rate between different momentum…