367 citations · 3.1k across the 85 of their papers we have counts for
18 papers · 1 filter
Formation of dynamical Schrödinger cats in low-dimensional ultracold attractive Bose gases
Alexej I. Streltsov, Ofir E. Alon, Lorenz S. Cederbaum
Dynamical Schrödinger cats can be formed when a one-dimensional attractive Bose-gas cloud is scattered off a potential barrier. Once formed, these objects are stable in time. The p…
Reduced density matrices and coherence of trapped interacting bosons
Kaspar Sakmann, Alexej I. Streltsov, Ofir E. Alon +1
The first- and second-order correlation functions of trapped, interacting Bose-Einstein condensates are investigated numerically on a many-body level from first principles. Correla…
Build-up of coherence between initially-independent subsystems: The case of Bose-Einstein condensates
O. E. Alon, A. I. Streltsov, L. S. Cederbaum
When initially-independent subsystems are made to contact, {\it coherence} can develop due to interaction between them. We exemplify and demonstrate this paradigm through several s…
Formation and dynamics of many-boson fragmented states in attractive one-dimensional ultra-cold gases
Alexej I. Streltsov, Ofir E. Alon, Lorenz S. Cederbaum
Dynamics of attractive ultra-cold bosonic clouds in one dimension are studied by solving the many-particle time-dependent Schrödinger equation. The initially coherent wave-packet c…
On-top fragmentation stabilizes atom-rich attractive Bose-Einstein condensates
Lorenz S. Cederbaum, Alexej I. Streltsov, Ofir E. Alon
It is well known that attractive condensates do not posses a stable ground state in three dimensions. The widely used Gross-Pitaevskii theory predicts the existence of metastable s…
The multi-configurational time-dependent Hartree method for bosons: Many-body dynamics of bosonic systems
Ofir E. Alon, Alexej I. Streltsov, Lorenz S. Cederbaum
The evolution of Bose-Einstein condensates is amply described by the time-dependent Gross-Pitaevskii mean-field theory which assumes all bosons to reside in a single time-dependent…
Interferences in the density of two Bose-Einstein condensates consisting of identical or different atoms
L. S. Cederbaum, A. I. Streltsov, Y. B. Band +1
The density of two {\it initially independent} condensates which are allowed to expand and overlap can show interferences as a function of time due to interparticle interaction. Tw…
Role of excited states in the splitting dynamics of interacting Bose-Einstein condensates when ramping-up a barrier
Alexej I. Streltsov, Ofir E. Alon, Lorenz S. Cederbaum
An essentially-exact approach to compute the wavefunction in the time-dependent many-boson Schrödinger equation is derived and employed to study accurately the process of splitting…
Cold atoms in real-space optical lattices
Ofir E. Alon, Alexej I. Streltsov, Lorenz S. Cederbaum
Cold atoms in optical lattices are described in {\it real space} by multi-orbital mean-field Ansätze. In this work we consider four typical systems: (i) spinless identical bosons,…
Time-dependent multi-orbital mean-field for fragmented Bose-Einstein condensates
O. E. Alon, A. I. Streltsov, L. S. Cederbaum
The evolution of Bose-Einstein condensates is usually described by the famous time-dependent Gross-Pitaevskii equation, which assumes all bosons to reside in a single time-dependen…
Interferences in the density of two initially independent Bose-Einstein condensates
L. S. Cederbaum, A. I. Streltsov, Y. B. Band +1
It is shown that the density of two {\it initially independent} condensates which are allowed to expand and overlap can show interferences as a function of time due to interparticl…
Phase separations of bosonic mixtures in optical lattices from macroscopic to microscopic scales
Ofir E. Alon, Alexej I. Streltsov, Lorenz S. Cederbaum
Mixtures of cold bosonic atoms in optical lattices undergo phase separations on different length scales with increasing inter-species repulsion. As a general rule, the stronger the…
General variational many-body theory with complete self-consistency for trapped bosonic systems
Alexej I. Streltsov, Ofir E. Alon, Lorenz S. Cederbaum
In this work we develop a complete variational many-body theory for a system of trapped bosons interacting via a general two-body potential. In this theory both the many-body b…
Coupled-Cluster Theory for Systems of Bosons in External Traps
Lorenz S. Cederbaum, Ofir E. Alon, Alexej I. Streltsov
A coupled-cluster approach for systems of bosons in external traps is developed. In the coupled-cluster approach the exact many-body wavefunction is obtained by applying an exp…
Exact ground state of finite Bose-Einstein condensates on a ring
Kaspar Sakmann, Alexej I. Streltsov, Ofir E. Alon +1
The exact ground state of the many-body Schrödinger equation for bosons on a one-dimensional ring interacting via pairwise -function interaction is presented for up to fifty…
Pathway from condensation via fragmentation to fermionization of cold bosonic systems
Ofir E. Alon, Lorenz S. Cederbaum
For small scattering lengths, cold bosonic atoms form a condensate the density profile of which is smooth. With increasing scattering length, the density {\it gradually} acquires m…
Zoo of quantum phases and excitations of cold bosonic atoms in optical lattices
Ofir E. Alon, Alexej I. Streltsov, Lorenz S. Cederbaum
Quantum phases and phase transitions of weakly- to strongly-interacting bosonic atoms in deep to shallow optical lattices are described by a {\it single multi-orbital mean-field ap…
Continuous configuration-interaction for condensates in a ring
Ofir E. Alon, Alexej I. Streltsov, Kaspar Sakmann +1
A continuous configuration-interaction approach for condensates in a ring is introduced. In its simplest form this approach utilizes for attractive condensates the Gross-Pitaevskii…