QUIN-PINEM · Quantum Interactions in Photon-Induced Nearfield Electron Microscopy

Breakthroughs in electron microscopy over the past 15 years have introduced femtosecond laser-driven electron microscopes that probe matter and even hybrid light-matter polaritons with ultrafast time resolution. However, such systems still mostly extract classical properties of light and matter. This project will pursue the next frontier – extract quantum properties of light and matter, such as correlations and entanglement. We will develop a new concept of laser-driven electron interferometry for the goal of creating and measuring quantum correlations in the ultrafast regime.Over the past 4 years, my group has shown how free electrons can interact coherently with light in photonic cavities and even get imprinted by the quantum photon statistics of light. Leveraging such interactions enabled us and other groups to develop theories and experiments for controlling the wave nature of individual electrons, creating coherently modulated electron wavepackets.Here we will harness such coherent electron modulation to develop new microscopy modalities that can reveal important quantum properties of light, matter, and their interactions: We are going to make the first observation of quantum nonlinear optical dynamics of polaritons in 2D materials, to measure the quantum state dynamics in superradiant quantum dot ensembles, and to capture the spatiotemporal dynamics of correlated matter, such as the creation and annihilation of vortices in superconductors.Toward this goal, we will develop a unique ultrafast free-electron interferometer operating at cryogenic temperatures. Exploiting the quantum electron-photon interaction in this system can create unprecedented many-electron entangled states that break classical limits in electron microscopy. Specially designed photonic cavities will amplify the entanglement and promote electron microscopy as a novel platform for fundamental studies of quantum information science.