****TECHNICAL ABSTRACT**** This program studies novel collective quantum phenomena using a new semiconductor cavity system with strong matter-light couplings. It builds on the recent advancement in both photonic crystals and polaritons - strongly coupled semiconductor exciton-photon modes. The new cavity structure integrates a designable photonic-crystal mirror to enable not only flexible control of the polaritons, but also coherent coupling of multiple polariton systems, thereby opening a new path in polariton research beyond condensation physics. Physics of perplexing collective quantum phenomena will be elucidated by new controls over the quantum gas. Novel quantum phenomena will be sought after by purposeful design of the fundamental properties of the system. Manybody Hamiltonian will be investigated and modeled with coupled-polariton lattices. The research will improve our fundamental understanding of matter-light interactions and collective quantum phenomena, and will provide an experimental platform at the research frontier interfacing cavity-quantum-electrodynamics, manybody physics, and quantum simulation. Public lectures, international summer schools, and K-12 science competitions will be held to disseminate the knowledge and cultivate interest in science.
Quantum mechanics is the language for the microscopic world of single or few particles like photons and atoms. When the number of particles grows large, interactions destroys quantum correlations among the particles and the system enters the classical world. In some special cases, however, quantum correlations survive among a macroscopic number of particles in a macroscopically large system leading to remarkable collective quantum phenomena and their applications. Examples include lasers, superconductors, and Bose-Einstein Condensation of atomic gasses used in precision measurements. This CAREER program will create, control and simulate novel collective quantum phenomena in a uniquely designable and scalable system, on a solid-state platform, with a built-in matter-light interface, at temperatures many orders of magnitude higher than required by, e.g., atomic gases. This will be accomplished by developing a new cavity structure for a matter-light hybrid quantum gas: the semiconductor microcavity polaritons. The research will consist of a synergy of computer-aided design and modeling, nano-fabrication, and advanced spectroscopy and quantum optical measurements. Through the cutting edge research, young scientists will be recruited and trained as the future leaders in science and technology. The knowledge of abstract quantum phenomena and their connection to people's daily lives will be communicated to a broad audience via public lectures and international summer schools. Physics competitions and demos will be organized to cultivate interest in science among K-12 students. The creation of collective quantum phenomena on a technologically practical platform will lay the groundwork for future quantum technologies, such as quantum light sources with ultra-low energy threshold, ultrafast opto-spintronics devices, and quantum simulators.
