Extended Wannier-Stark ladder and particle-pair Bloch oscillations in dimerized non-Hermitian systems
arXiv:2404.02399 · doi:10.1103/PhysRevB.110.064310
Abstract
In the Hermitian regime, the Wannier-Stark ladder characterizes the eigenstates of an electron in a periodic potential with an applied static electric field. In this work, we extend this concept to the complex regime for a periodic non-Hermitian system under a linear potential. We show that although the energy levels can be complex, they are still equally spaced by a real Bloch frequency. This ensures single-particle Bloch oscillations with a damping (or growing) rate. The system can also support standard two-particle Bloch oscillations under certain conditions. We propose two types of dimerized non-Hermitian systems to demonstrate our results. In addition, we also propose a scheme to demonstrate the results of electron-pair dynamics in a single-particle 2D -symmetric square lattice.
8 pages, 5 figures
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