DMREF: III-nitride Monolayers and Extreme Quantum Dots

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Nontechnical DescriptionThe project will serve the Materials Genome Initiative by creating a new family of nano-quantum materials (nQMs) that are confined down to a few atoms. In partnership with Sandia National Labs and Air Force Research Lab, the research will establish a nQM platform with unique quantum functionalities by using the most accurate quantum theory to design the quantum optoelectronic properties of nQMs. The nQMs will establish a unique controllably interacting semiconductor qubit platform needed for quantum information science application, including the possibility to control many-body states in two-dimensional (2D) materials. The project will develop ordered extreme quantum dots (XQD) arrays with state-of-the-art growth and metrology facilities. The research breakthroughs have the potential to dramatically enhance the efficiency AlGaN-based deep UV LEDs. This would create the much-needed technology for replacing conventional mercury lamps in water and air purification as well as sterilization, thereby eliminating mercury emissions and significantly reducing electricity consumption. The highly interdisciplinary nature and the appealing potential social impacts of the research will be leveraged to encourage underrepresented minorities and women in careers in science and engineering. At the same time, the research will provide opportunity to involve undergraduate students in frontier research. Through the popular “Saturday Morning Physics” public lecture series at the University of Michigan, the project will educate the broader public on quantum science and technology.Technical DescriptionThe focused theory-epitaxy-characterization-quantum optoelectronics collaborative research will develop a systematic quantum theory that integrates three first-principles methods, including Density-Functional Theory, Many-Body Perturbation Theory, and Quantum-Dynamic Cluster Expansion, to precisely predict and determine the electronic, optical, excitonic, and entanglement properties of III-nitride quantum nanostructures. The presence of disorder and spectral diffusion, deleterious effects that plague conventional quantum dots, will be addressed by i) deterministically growing and positioning XQDs on hBN whose atomically smooth surface eliminates any interface interdiffusion and disorder, and ii) creating interface excitons with well-aligned dipole and with emission wavelengths largely determined by the intrinsic band alignment of hBN/AlN. The combination of deterministic position, size, and type of excitons within XQD qubits provides a new level of flexibility to adjust quantum-light emission as well as qubit–qubit and XQD–2D exciton interactions by orders of magnitude. The research will combine deep-UV time-resolved photoluminescence spectroscopy and differential transmission spectroscopy to demonstrate controllable XQD–XQD coupling as well as the controlled formation of direct and indirect excitons, biexcitons, and dropletons at room temperature. The realization of controllably interacting qubits with III-nitride nQMs will establish the detection, source, and processing of entanglement on a common semiconductor platform that has a known and established industrial-level scalability. Furthermore, the potential of the nQMs platform will be demonstrated by taking key steps toward extraordinary quantum optoelectronic devices, including deep UV light emitters and coupled XQD systems.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.