Related papers: Nambu-Goldstone modes in segregated Bose-Einstein …
We study the generation of two-mode entanglement in a two-component Bose-Einstein condensate trapped in a double-well potential. By applying the Holstein-Primakoff transformation, we show that the problem is exactly solvable as long as the…
We present a detailed study of the spectrum and dispersion of Bogoliubov quasiparticles in two coupled elongated Bose-Einstein condensates. We develop an analytically solvable model that approximates two infinite homogeneous condensates and…
We present a scheme for determining if the quantum state of a small trapped Bose-Einstein condensate is a state with well defined number of atoms, a Fock state, or a state with a broken U(1) gauge symmetry, a coherent state. The proposal is…
An exact diagonalization study reveals that a matter-wave bright soliton and the Goldstone mode are simultaneously created in a quasi-one-dimensional attractive Bose-Einstein condensate by superpositions of quasi-degenerate low-lying…
We present new features of low energy Bogoliubov quasiparticle excitations of a two component Bose-Einstein condensate (TBEC) in quasi-2D geometry at zero temperature using Hartree-Fock-Bogoliubov (HFB). We, in particular, consider the…
We study some effects arising from periodic modulation of the asymmetry and the barrier height of a two-well potential containing a Bose-Einstein condensate. At certain modulation frequencies the system exhibits resonances, which may lead…
In non-relativistic systems, when there is spontaneous symmetry breaking, the number of Nambu-Goldstone bosons ($n_{NG}$) are not necessarily equal to the number of broken generators ($n_{BG}$). Here we use the method of operators for…
We employ the diagrammatic Monte Carlo method based on lattice path-integral representaion of the particle sector and real-space diagrammatics of the phonon sector to study effects of optical phonon dispersion on Bose-Einstein condensation…
We consider the statics and dynamics of F = 1 spinor Bose-Einstein condensates (BECs) confined in double well potentials. We use a two-mode Galerkin-type quasi-analytical approximation to describe the stationary states of the system. This…
We reveal that Hopf solitons can be stabilized in rotating atomic Bose-Einstein condensate. The Hopfion is a matter-wave vortex complex which carries two independent winding numbers. Such a topological solitonic structure results from a…
A self-contained method of obtaining effective theories resulting from the spontaneous breakdown of conformal invariance is developed. It allows to demonstrate that the Nambu-Goldstone fields for special conformal transformations always…
We discuss the nature of symmetry breaking and the associated collective excitations for a system of bosons coupled to the electromagnetic field of two optical cavities. For the specific configuration realized in a recent experiment at ETH,…
A simple mechanism for SUSY breaking is proposed due to the coexistence of BPS domain walls. It requires no messenger fields nor complicated SUSY breaking sector on any of the walls. We assumed that our world is on a BPS domain wall and…
In the imaginay-time formalism of thermal field theory, and also in the real-time formalism but by means of some redefined physical propagators for scalar bound states by diagonalization of four-point function matrices, we reexamine the…
We show that the phenomenon of modulational instability in arrays of Bose-Einstein condensates confined to optical lattices gives rise to coherent spatial structures of localized excitations. These excitations represent thin disks in 1D,…
In condensed matter systems, zero-dimensional or one-dimensional Majorana modes can be realized respectively as the end and edge states of one-dimensional and two-dimensional topological superconductors. In this $\textit{top-down}$…
In this work, we uncover a universal relaxation mechanism of pinned density waves, combining Gauge/Gravity duality and effective field theory techniques. Upon breaking translations spontaneously, new gapless collective modes emerge, the…
We study composite solitons, consisting of domain walls and vortex lines attaching to the walls in two-component Bose-Einstein condensates. When the total density of two components is homogeneous, the system can be mapped to the O(3)…
Bose-Einstein condensates in a double-well potential contain the essential ingredients to study many-body systems within a rich classical phase-space that includes an unstable point and a separatrix. Employing a selfconsistent finite…
The fluctuations of a number of particles in the Bose-Einstein condensate are studied in the grand canonical ensemble with an effective single-mode Hamiltonian, which is derived from an assumption that the mode corresponding to the…