18 research outputs found
Dispersive hydrodynamics of nonlinear polarization waves in two-component Bose-Einstein condensates
We study one dimensional mixtures of two-component Bose-Einstein condensates in the limit where the intra-species and inter-species interaction constants are very close. Near the mixing-demixing transition the polarization and the density dynamics decouple. We study the nonlinear polarization waves, show that they obey a universal (i.e., parameter free) dynamical description, identify a new type of algebraic soliton, explicitly write simple wave solutions, and study the Gurevich-Pitaevskii problem in this context
Mixed-isotope Bose-Einstein condensates in Rubidium
We consider the ground state properties of mixed Bose-Einstein condensates of
87Rb and 85Rb atoms in the isotropic pancake trap, for both signs of the
interspecies scattering length. In the case of repulsive interspecies
interaction, there are the axially-symmetric and symmetry-breaking ground
states. The threshold for the symmetry breaking transition, which is related to
appearance of a zero dipole-mode, is found numerically. For attractive
interspecies interactions, the two condensates assume symmetric ground states
for the numbers of atoms up to the collapse instability of the mixture.Comment: Revised; 21 pages, 5 figures, submitted to Physical Review
Accessing and Manipulating Dispersive Shock Waves in a Nonlinear and Nonlocal Rydberg Medium
Dispersive shock waves (DSWs) are fascinating wave phenomena occurring in
media when nonlinearity overwhelms dispersion (or diffraction). Creating DSWs
with low generation power and realizing their active controls is desirable but
remains a longstanding challenge. Here, we propose a scheme to generate
weak-light DSWs and realize their manipulations in an atomic gas involving
strongly interacting Rydberg states under the condition of electromagnetically
induced transparency (EIT). We show that for a two-dimensional (2D) Rydberg gas
a weak nonlocality of optical Kerr nonlinearity can significantly change the
edge speed of DSWs and induces a singular behavior of the edge speed and hence
an instability of the DSWs. However, by increasing the degree of the Kerr
nonlocality, the singular behavior of the edge speed and the instability of the
DSWs can be suppressed. We also show that in a 3D Rydberg gas, DSWs can be
created and propagate stably when the system works in the intermediate
nonlocality regime. Due to the EIT effect and the giant nonlocal Kerr
nonlinearity contributed by the Rydberg-Rydberg interaction, DSWs found here
have extremely low generation power. In addition, an active control of DSWs can
be realized; in particular, they can be stored and retrieved with high
efficiency and fidelity through switching off and on a control laser field. The
results reported here are useful not only for unveiling intriguing physics of
DSWs but also for finding promising applications of nonlinear and nonlocal
Rydberg media.Comment: 20 pages, 13 figure
Dispersive shock waves in nonlinear and atomic optics
A brief review is given of dispersive shock waves observed in nonlinear optics and dynamics of Bose-Einstein condensates. The theory of dispersive shock waves is developed on the basis of Whitham modulation theory for various situations taking place in these two fields. In particular, the full classification is established for types of wave structures evolving from initial discontinuities for propagation of long light pulses in fibers with account of steepening effect and for dynamics of the polarization mode in two-component Bose-Einstein condensates
Accessing and Manipulating Dispersive Shock Waves in a Nonlinear and Nonlocal Rydberg Medium
Dispersive shock waves (DSWs) are fascinating wave phenomena occurring in media when nonlinearity overwhelms dispersion (or diffraction). Creating DSWs with low generation power and realizing their active controls is desirable but remains a longstanding challenge. Here, we propose a scheme to generate weak-light DSWs and realize their manipulations in an atomic gas involving strongly interacting Rydberg states under the condition of electromagnetically induced transparency (EIT). We show that for a two-dimensional (2D) Rydberg gas a weak nonlocality of optical Kerr nonlinearity can significantly change the edge speed of DSWs, and induces a singular behavior of the edge speed and hence an instability of the DSWs. However, by increasing the degree of the Kerr nonlocality, the singular behavior of the edge speed and the instability of the DSWs can be suppressed. We also show that in a 3D Rydberg gas, DSWs can be created and propagate stably when the system works in the intermediate nonlocality regime. Due to the EIT effect and the giant nonlocal Kerr nonlinearity contributed by the Rydberg-Rydberg interaction, DSWs found here have extremely low generation power. In addition, an active control of DSWs can be realized; in particular, they can be stored and retrieved with high efficiency and fidelity through switching off and on a control laser field. The results reported here are useful not only for unveiling intriguing physics of DSWs but also for finding promising applications of nonlinear and nonlocal Rydberg media
Dispersive shock waves in nonlinear and atomic optics
A brief review is given of dispersive shock waves observed in nonlinear optics and dynamics of Bose-Einstein condensates. The theory of dispersive shock waves is developed on the basis of Whitham modulation theory for various situations taking place in these two fields. In particular, the full classification is established for types of wave structures evolving from initial discontinuities for propagation of long light pulses in fibers with account of steepening effect and for dynamics of the polarization mode in two-component Bose-Einstein condensates