****Technical Abstract**** This award supports experiments which will probe dynamics of strongly interacting electronic states in nanostructures with the goal of identifying characteristic time scales that separate adiabatic and non-adiabatic regimes, and improving our understanding of non-adiabatic transport in such systems. Using Kondo-correlated states in single-electron transistors as the model, we will characterize transport through the device by measurements of time-averaged current and by a direct measurement of the frequency-dependent SET impedance, a complementary technique which is expected to provide a direct link between experiments and theory. Dynamic aspects of transport in quantum point contacts will be investigated, which will help further understand the role of spin correlation in this fundamental mesoscopic system. The work will complement existing studies of correlated dynamics in bulk materials and will benefit researchers pursuing coherent control of elementary quantum states and those interested in general aspects of quantum dynamics on the nanoscale. The proposed project will integrate research and education goals by supporting the training of a graduate student and undergraduates in modern science and technology, developing teaching experiments for a new course on modern experimental methods and the "physics of everyday life" online course, and offering a summer research camp for a physics teacher and several students on experimental projects related to the main program.
Quantum mechanics describes behavior of small building blocks of matter, such as electrons in conductors. Understanding quantum behavior on the most basic scale which involves but a few electrons is widely believed to lead to an improved ability to synthesize materials with finely tailored properties and to advances in developing a fundamentally novel class of electronic devices. One of the challenges is to find accurate methods for predicting behavior of a quantum system that strongly interacts with its environment. This project will focus on the quantum mechanics of a single electronic spin embedded in a conductor, known as Kondo state, and investigate how the state responds to a time-dependent perturbation. The combination of strong interactions with the environment and presence of time-dependent signals is to occur in any solid-state quantum electronic device, and insufficient data are presently available in such a regime for testing theoretical models. One of the questions is how the response of the quantum system with strong interactions changes with the frequency of the applied signal. This project will identify relevant characteristic frequencies and examine the predicted connection between those and the strength of the interaction with the environment, and generate data in the "fast" regimes where novel theories are being developed. The work contributes to the training of skilled technical workforce and contains an integrated education plan to develop a course on modern experimental methods, offer a summer research camp to a physics teacher and several students on experimental projects related to the main program, and construct demonstrations that convey complicated physics topics in a clear visual form to be used in an online "physics of everyday life" course for non-science majors.
