Realizing PT-symmetric non-Hermiticity with ultra-cold atoms and   Hermitian multi-well potentials
  We discuss the possibility of realizing a non-Hermitian, i.e. an open two-well system of ultra-cold atoms by enclosing it with additional time-dependent wells that serve as particle reservoirs. With the appropriate design of the additional wells PT-symmetric currents can be induced to and from the inner wells, which support stable solutions. We show that interaction in the mean-field limit does not destroy this property. As a first method we use a simplified variational ansatz leading to a discrete nonlinear Schr\"odinger equation. A more accurate and more general variational ansatz is then used to confirm the results. 
Manuel Kreibich, J\"org Main, Holger Cartarius, G\"unter Wunner
quant-ph cond-mat.quant-gas nlin.CD