Remanent switching of Bloch-polaritons

• Applicant: Dr. Chris Sturm
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 390089887

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.

• DFG Programme: Research Grants