ABSTRACT
Quantum phase transition is one of the most interesting aspects in quantum many-body systems. Recently, geometric quantum discord has been introduced to signature the critical behavior of various quantum systems. However, it is well-known that topological quantum phase transition can not be described by the conventional Landau's symmetry breaking theory, and thus it is unknown that whether previous study can be applicable in this case. Here, we study the topological quantum phase transition in Kitaev's 1D p-wave spinless quantum wire model in terms of its ground state geometric quantum discord. The derivative of geometric quantum discord is nonanalytic at the critical point, in both zero temperature and finite temperature cases. The scaling behavior and the universality are verified numerically. Therefore, our results clearly show that all the key ingredients of the topological phase transition can be captured by the nearest neighbor and long-range geometric quantum discord.
ABSTRACT
In this paper, we theoretically investigate the propagation properties of probe and mixing fields in a quantum well waveguide. This waveguide is driven by two strong control (pumping and coupling) fields and a weak probe field. Under appropriate parameters condition, the electron spin coherence can suppress the absorption and enhance the nonlinear susceptibilities of the probe (or mixing) field. This study reveals that probe (or mixing) field can form soliton pairs and propagate in the quantum well waveguide with slow group velocity. We also study the soliton collision and dynamics evolution. The results show that the propagation of soliton can be strongly modified by the electron spin coherence.
