2,604 research outputs found
Chimera patterns in conservative systems and ultracold atoms with mediated nonlocal hopping
Chimera patterns, characterized by coexisting regions of phase coherence and
incoherence, have so far been studied in non-conservative systems with
dissipation. Here, we show that the formation of chimera patterns can also be
observed in conservative Hamiltonian systems with nonlocal hopping in which
both energy and particle number are conserved. Effective nonlocality can be
realized in a physical system with only local coupling if different time scales
exist, which can be illustrated by a minimal conservative model with an
additional mediating channel. Finally, we show that the patterns should be
observable in ultracold atomic systems. Nonlocal spatial hopping over up to
tens of lattice sites with independently tunable hopping strength and on-site
nonlinearity can be implemented in a two-component Bose-Einstein condensate
with a spin-dependent optical lattice, where the untrapped component serves as
the matter-wave mediating field. The present work highlights the connections
between chimera patterns, nonlinear dynamics, condensed matter, and ultracold
atoms.Comment: 4 figures with supplementar
Revisiting entanglement within the Bohmian approach to quantum mechanics
We revisit the concept of entanglement within the Bohmian approach to quantum mechanics. Inspired by Bohmian dynamics, we introduce two partial measures for the amount of entanglement corresponding to a pure state of a pair of quantum particles. One of these measures is associated with the statistical correlations exhibited by the joint probability density of the two Bohmian particles in configuration space. The other partial measure corresponds to the correlations associated with the phase of the joint wave function, and describes the non-separability of the Bohmian velocity field. The sum of these two components is equal to the total entanglement of the joint quantum state, as measured by the linear entropy of the single-particle reduced density matrix.Fil: Zander, Claudia. University of Pretoria; SudáfricaFil: Plastino, Ángel Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Junín); Argentin
Three-dimensional topological solitons in PT-symmetric optical lattices
We address the properties of fully three-dimensional solitons in complex parity-time (PT)-symmetric periodic lattices with focusing Kerr nonlinearity, and uncover that such lattices can stabilize both fundamental and vortex-carrying soliton states. The imaginary part of the lattice induces internal currents in the solitons that strongly affect their domains of existence and stability. The domain of stability for fundamental solitons can extend nearly up to the PT-symmetry breaking point, where the linear lattice spectrum becomes complex. Vortex solitons feature spatially asymmetric profiles in the PT-symmetric lattices, but they are found to still exist as stable states within narrow regions. Our results provide the first example of continuous families of stable three-dimensional propagating solitons supported by complex potentials.Peer ReviewedPostprint (published version
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