This award supports theoretical research and education on nonlinear resonators and the how the microscopic quantum world leads to the macroscopic classical world of our everyday experience.
Nonlinear resonator systems can exhibit qualitative differences between their derived quantum and classical dynamical behavior. Both the nature and extent of these corresponding quantum-classical differences depend crucially on the strength and type of environment and measurement probe to which the resonator couples. Recent advances in the development of low-decoherence electronic devices that are strongly coupled to high quality factor mechanical or superconducting microwave resonators present an ideal opportunity to investigate the quantum-classical correspondence for these nonlinear resonator-environment systems. Such an investigation is relevant for understanding how the macroscopic classical world emerges by approximation from the quantum world, as well as for the very practical task to develop quantum-limited measurement schemes that exploit the resonator system nonlinearities.
The PI research consists of two nonlinear resonator projects. In project one, the PI will develop the theory for recent and planned experiments that investigate the dynamics of a macroscopic mechanical resonator interacting piezoelectrically with electrons tunneling through a quantum point contact that is embedded in the resonator. In project two, the PI will develop the theory for experiments underway that investigate the dynamics of a novel, low noise superconducting microwave resonator scheme with embedded Josephson junction device.
The projects will provide training for one graduate student and two undergraduate students in the craft of theoretical physics, gaining expertise in such areas as many body theory, mesoscopic quantum physics, nonlinear dynamics, quantum optics, and advanced computing techniques.
NONTECHNICAL SUMMARY
This award supports theoretical research and education to study the operation of resonators that lie precariously at the boundary of the world of quantum mechanics that governs the behavior electrons, atoms, and molecules, and the world of classical mechanics that we experience every day. Common examples of mechanical resonators include a pendulum that swings or a beam that vibrates at a characteristic frequency when plucked. To approach the quantum world, the mechanical resonators the PI will investigate are tiny beams some 10,000 times smaller than the width of a human hair. The PI will investigate more complex examples of resonators involving mechanical, electrical, and optical systems that are specially designed to probe the emergence of the classical world from the quantum mechanical world. The research is carried out in close connection to experiments and builds on fundamental principles of condensed matter and materials physics to test and to advance fundamental understanding of the world. One theme of the research is to advance our fundamental understanding of the limitations quantum mechanics places on how accurately physical quantities can be measured.
