When a strong interaction between light and matter occurs, new phenomena (entangled quantum states) arise, which are generally not observed in nature. This quantum entanglement can potentially be harnessed for quantum information technologies with drastically improved data acquisition and processing. In this project, the research team uses semiconductor nanowires, which are surrounded by metal nanoparticles to investigate the interaction between light (in the form of plasmons) and semiconductor (in the form of excitons). To achieve strong coupling and quantum entanglement, the morphology of this nanostructure is modified by laser processing inside a transmission electron microscope. The light-matter coupling is investigated with optical methods and electron microscopy along with theoretical modelling. This project opens new prospects for designing novel quantum materials with significant impact in the areas of quantum information and quantum science. The project fully integrates education and training of graduate and undergraduate students with an emphasis on recruitment from underrepresented groups. The training prepares the students for a wide range of careers. Outreach to the public includes contributions to local STEM programs and organized lab-tours of the electron microscopy facilities for high-school students.
Entanglement and strong coupling are the basis for quantum computing and quantum sensing. As a model system to study these quantum effects the research team is using an open cavity semiconductor nanowire-metal nanoparticle system in which excitons and plasmons can interact in regimes ranging from weak to strong coupling. Ultrafast optical spectroscopy and electron energy-loss spectroscopy are uniquely combined to study the energy transfer and many-emitter entanglement with high temporal and high spatial resolution. Laser processing of these plasmonic nanostructures inside the transmission electron microscope allows modifications of the morphology during atomic resolution imaging providing a system to achieve and to control quantum entanglement. The central thrusts in this project are to synthesize nano-morphologically controlled metal/organic/semiconductor nanowires and to study the coupling of excitons and plasmons. Both the change in the nanostructure morphology and the inserted organic modulator critically modify the coupling strength in this quantum system. The calculated dielectric response function connects the loss function obtained from the electron energy-loss spectroscopy measurements with the optical measurements. Complementary theoretical modelling provides a fundamental understanding of these light-matter interactions. The investigations of the research team open new prospects for designing novel quantum materials to exploit strong coupling and many-emitter entanglement with significant impact in the areas of quantum –information, -chemistry and -biology.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
