Remanent switching of Bloch-polaritons

该项目的目的是开发光子结构，使其能够在室温及以上温度下实现量子力学状态的非易失性开关（剩余和持久）。这是通过发展允许光子布洛赫表面模式与激子的电子系统耦合的结构来实现的，形成所谓的布洛赫极化子。通过共振激发，可以实现传播极化子凝聚。这些极化子的光子成分确保了几百微米以上的长距离传播和高表面灵敏度。利用这种高表面灵敏度，可以通过集成在结构表面的铁电材料来控制和改变布洛赫极化子的性质，如能量、动量、自旋和波函数的相位。通过施加电脉冲，铁电材料内的铁电极化将被创建或更确切地说改变。这种极化与相邻ZnO层的压电极化耦合导致光子结构的光学性质发生变化，从而导致布洛赫极化子的光学性质发生变化。布洛赫极化子性质变化的证明将用光学方法来完成。因此，这种方法允许对状态进行电写入和光读出。此外，布洛赫极化子的性质，如它们与环境的相互作用，它们的弛豫和散射行为，以及控制它们的性质的可能性，将在这个项目中进行详细的研究。这些性质在文献中没有讨论，因为布洛赫极化子非常有希望实现基于极化子的器件和集成光学，因为它们在传播长度和低温操作方面没有限制。

The aim of the project is to develop photonic structures which allows a non-volatile switching (remanently and persistently) of a quantum mechanical state at room temperature and above. This is reached by developing structures which allows the coupling of the photonic Bloch surface modes with the electronic system of the excitons, forming so-called Bloch-polaritons. By means of resonant excitation a propagating polariton condensate will be realized. The photonic component of these polaritons ensures the long range propagation over several hundreds of micrometre and a high surface sensitivity. This high surface sensitivity will be exploite in order to control and change the properties of the Bloch-polaritons, e.g. energy, momentum, spin and phase of the wave function, by means of a ferroelectric material which will be integrated at the surface of the structure. By applying an electric pulse, a ferroelectric polarisation within the ferroelectric material will be created or rather changed. The coupling of this polarisation with the piezoelectric one of an adjoin ZnO layer leads to a change of the optical properties of the photonic structure and therewith of the Bloch-polaritons. The proof of this change of the properties of the Bloch-polaritons will be done by optical methods. Therefore, this approach allows the electrically writing and the optical read-out of a state. Furthermore, the properties of Bloch-polaritons as their interaction with their environment, their relaxation and scattering behaviour as well as the possibilities to control their properties will be investigated in detail within this project. These properties are not discussed in the literature and are of special interest since Bloch-polaritons are very promising for the realization of devices and integrated optics based on polaritons since they do not exhibit limitations with respect to their propagation length and an operation at low temperatures.