Studying Bloch Oscillation And Wannier Stark Ladder In Superlattice

Since Bloch oscillation and Wannier-stark-ladder were predicted theoretically, many physics were attracted by them. At the late eighties, Bloch oscillation and Wannier-stark-ladder were observed in the superlattice, which made a great development on the experiment and theoretical analysis.Sectionâ… , after explain the physical interpretation of Bloch oscillation and Wannier-stark-ladder, we also study the research status for them. At last, we give some reasons for that why it is so important to study Bloch oscillation and Wannier-stark-ladder.Sectionâ…¡, We mainly deduce the Bloch theorem in some details, and get some useful inference.Sectionâ…¢, we firstly calculate the Bloch oscillation and Wannier-stark-ladder, when the ultracold-atom in optical lattice potential field subject to an external force which is a constant field effect. Furthermore, based on this model, we also discussed result when the external dc force F(z) is changing along with the z direction. At last, we compare these two cases.Sectionâ…£, for the most general one-band wave packet, the energy uncertainty of a Bloch electron in an external electric field is on the order of the Stark ladder spacing eEa, which is comparable in magnitude. At this section, we calculate the the energy uncertainty of Wannier-stark-ladder of ultracold-atom in optical lattice potential.