固体激子极化激元玻色-爱因斯坦凝聚中的非线性效应研究

The excitons (created in the quantum well, placed in an antinode of a microcavity photon mode) and photon modes are in the strong coupling regime, and the appropriate description of the quantum system relies on composite Bose quasiparticles, called polaritons. Large amounts of polaritons accumulate in the lower dressed state coupled by photon modes and excitons to form exciton-polariton Bose-Einstein condensation (BEC). In this project, some nonlinear research works would be done in exciton-polariton BEC, such as the creation and propagation of soliton, the effect of spin polarization on nonlinear effect of exciton-polariton BEC and corresponding nonlinear controlling. The detailed contents would include three parts: 1) the research around nonlinear localized objects such as solitons. We would like to discuss the conditions to observe solitons and the underlying physics for it as well as analyze the interaction between different solitons. 2) the research around multi-component exciton-polariton BEC with different spin polarization. We would focus on the interaction between different polariton components, to see whether they have apparent effect on the dynamical process of exciton-polariton BEC and discuss whether it is possible to observe the nonlinear phenomena relative to the spin polarization such as half-quantum vortices. 3) to discuss the possibility to realize the polariton transistor in all kind of exciton-polariton BEC systems such as homogeneous, inhomogeneous, with only one spin polarization or two. The work for this project would further fulfill the research in exciton-polariton BEC and deepen the understanding for the underlying physics. Additionally, it would promote the development of new optical materials and settings and fasten the underlying application in some fields such as quantum information communication.

微腔结构中光模与电子和空穴对构成的激子耦合产生缀饰态，大量玻色混合物（极化激元）占据低缀饰态中能量最低态，称之为半导体微腔激子极化激元玻色-爱因斯坦凝聚。本项目拟对该凝聚中的非线性效应及其操控展开研究，例如孤子的产生和传播，自旋极化对非线性作用的影响以及相应的非线性操控等。 具体研究内容共分为三部分：1）展开单自旋固体凝聚中非线性局域化对象孤子的研究，探讨其存在的条件，分析其潜在物理机制及孤子间的相互作用；2）对多自旋固体凝聚展开研究，探讨不同自旋极化成分的相互作用对凝聚动态演化过程的影响，探讨与自旋极化相关的非线性特性例如半量子涡旋存在的可能性；3）就单自旋、多自旋、均匀介质以及非均匀介质探讨实现极化激元晶体管的可能性。 本项目的完成除了可以进一步完善固体激子极化激元凝聚理论，深化人们对其本质的认识外，还将有效促进新型光学材料和器件的开发，加快实现其在量子信息通讯等领域的潜在价值。

光电子玻色爱因斯坦凝聚具有以下几方面的特性：微纳尺度，强非线性导致的低阈值，近室温条件下实现凝聚，固态器件化。这几个特性使得该领域的相关研究在量子信息以及量子计算方面具有重要的应用基础，因而近年来受到越来越多的关注。.本项目研究了光电子玻色爱因斯坦凝聚中的非线性效应，研究成果分为三部分：1）选择合适的理论模型，研究标量孤子在光电子凝聚中的存在条件，演化方式以及稳态行为；2）寻找合适的模型解决凝聚体粒子间的排斥效应导致的矢量半孤子或半涡旋现象；3）在前期工作基础上考虑孤子在信息传输方面的应用。.本项目研究进一步完善了室温下微纳尺度的固态凝聚体系的非线性研究理论，深化了人们对孤子在该体系中的产生和动态演化的认识，并将所获得的规律性认识与量子信息物理相结合，进行了量子记忆过程的研究以及释放信号的动态操控。