Coherent GHz electro-optomechanics with polaromechanical crystals

• Applicants: Dr. Alexander Kuznetsov; Dr. Paulo V. Santos
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 359162958

We have recently demonstrated the coherent interaction between condensates and GHz acoustic phonons confined in traps inside a semiconductor microcavity (DFG project no. 359162958). The phonon-dressed polariton quasi-particles (simply, MCPPs) emerging from this interaction form the basis for a novel semiconductor-based platform for optomechanics in the GHz frequency range using electrically and optically stimulated GHz phonons. The aim of the follow-up project is to study the temporal and spatial coherent optomechanical interactions of MCPPs in single traps and trap lattices of low dimensions (trap sizes down to sub-µm). The reduced dimensionality will enhance polariton-phonon interactions as well as enable novel, phonon-mediated inter-site coupling mechanisms. Specifically, we will study (i) control of the polariton-phonon interaction by confinement. Here, we will engineer MCPP traps, molecules and arrays with sub-μm dimensions to explore phonon-polariton interaction down to a few-particle level and develop techniques for the optical and electrical generation and detection of stimulated coherent phonons. (ii) We will investigate hybridization of MCPP states in molecules as well as their interactions with piezoelectrically and impulsively generated strain fields. The experiments will be accompanied by theoretical investigations to elucidate coupling mechanisms. One of the outcomes will be the demonstration of the coherent optomechanical control (cooling and amplification) mediated by phonon sidebands. We will realize (iii) scalable MCPP interactions in 1D and 2D (extended coupled systems) optomechanical crystals. Precise control of the coupling between the traps will allow us to demonstrate a phonon analogue of a quantum cascade laser for the enhanced phonon generation as well as energy locking and synchronization of coupled MCPPs. These scalable MCPP arrays will be explored for efficient bi-directional conversion between near-infrared and microwave domains.

• DFG Programme: Research Grants
• International Connection: Argentina
• Cooperation Partners: Professor Dr. Axel Bruchhausen; Professor Dr. Alejandro Fainstein; Dr. Andres Reynoso; Professor Dr. Gonzalo Usaj