Nondecaying Bloch modes of a dissipative lattice

作者：Shchesnovich V S^*; Konotop V V

来源：EPL, 2012, 99(6): 60005.

DOI：10.1209/0295-5075/99/60005

We consider a Bose-Einstein condensate in a periodic optical lattice having a periodic sublattice of dissipative sites (which we call the dissipative lattice). The optical analog of this system consisting of lossy optical waveguides arranged in a checkerboard order is also presented. Using numerical simulations within the mean-field theory we demonstrate the existence of nondecaying (or propagating, in optical applications) Bloch-like coherent modes, which are eigenstates of the non-Hermitian operator with the dissipative lattice serving as a spatially periodic potential. The nondecaying modes have the Bloch index confined to the boundary of the Brillouin zone of the dissipative lattice. Besides the numerical simulations for a finite lattice, we use the Fourier space perturbation theory for a weak dissipative lattice and the single-band tight-binding approximation for a strong lattice to show that the effect is a universal property of the dissipative lattice.

• 出版日期2012-9