Polaritonics using two-dimensional atomic crystals

Cuny City College, New York NY

Investigators

Abstract

Title: Ultrafast switching architectures based on half-light half-matter quasiparticles (microcavity polaritons) in two-dimensional crystalline semiconductors The field of photonics has had tremendous impact on our lives through applications in telecommunication, display technology, medicine, sensing, entertainment, alternative energy systems and in semi-futuristic technologies such as quantum informatics. The next generation photonic systems and subsystems used in these applications will need to operate at ultrafast rates (Tbps) and should be capable of performing all-optical data routing and processing even at few photon levels. In this context, effort has mostly been directed towards realizing purely photonic switching architectures to replace their electronic counterparts resulting in larger power requirement and bigger footprint. This issue is addressed here by exploiting hybrid systems that take the best of electronics and photonics. Specifically, the switching architectures will rely on half-light half-matter quasiparticles called microcavity polaritons realized in two-dimensional crystalline semiconductors. They are expected to be an ideal platform to realize low energy, ultrafast, wide bandwidth, switches and gates for signal processing at classical and quantum levels, and image processing. The study will also contribute to fundamental understanding of light-matter interaction at the nanoscale. This work will provide unique inter-disciplinary scientific education in an emerging field encompassing optics, materials science and condensed matter physics to graduate, undergraduate and high school students from diverse socio-economic backgrounds and under-represented communities. Technical: Exploiting the benefit of both photons and matter, this research program will investigate light-matter quasiparticles (microcavity polaritons) as a platform for ultrafast low energy switching and signal processing. Specifically, microcavity polaritons formed by the strong coupling between the two-dimensional excitons of transition metal dichalcogenides and cavity photons will be utilized. By combining the novel physical properties of the two-dimensional materials such as valley and spin degrees of freedom, microcavity polariton switches that perform both intensity and polarization switching at room temperature will be developed. In addition, these switches will be integrated to demonstrate logic gate operations. Fourier space spectroscopy and pump-probe techniques will be used to characterize the nonlinear polariton emission and the switching dynamics. The development of room temperature polaritonic switching and logic elements represents a significant departure and advancement from traditional photon based or electron based signal processing systems.