Shedding Light on Quantum Interactions in New Correlated Electronic States of Matter
Kyle Shen studies exotic materials so that he can learn how electrons behave when they're flowing through them. His work could one day lead to more versatile superconductors and magnetic devices of all kinds, from better computers to more energy efficient high-speed trains. These materials are created using molecular beam epitaxy (MBE), a process invented in the 1960s in which various types of materials are evaporated and then deposited on a crystalline substrate under high-vacuum conditions. In collaboration with Cornell Prof. Darrell Schlom, in Materials Science and Engineering, Shen creates and studies new materials which can be thought of as atomic-scale "sandwiches" created by MBE. The second step in this process is to track the motion and interaction of electrons in these new materials. To do this Shen uses a method called photoemission spectroscopy, which depends on a principle known as the "photoelectric effect." This effect occurs when electrons are emitted from matter after absorbing electromagnetic radiation, such as X-rays or ultraviolet light. Shen is using some of the world's most advanced photoemission spectroscopy equipment. "This powerful new tool will provide insights into the underlying mechanisms of phenomena such as exotic superconductivity and colossal magnetoresistance (CMR)," he says. (CMR refers to a property of some materials that allows them to dramatically change electrical resistance, by many orders of magnitude, with the application of a magnetic field.)
Shen's teaching proposal focuses on encouraging undergraduate students to develop the skills they'll need to tackle the complex problems they will soon encounter in research or industry. "Real-world problems often don't have exact analytical solutions," he says, "and that requires new ways of thinking." Shen will address this need by developing a new class on "Estimation, Approximation, and Numerical Methods in Physics."It will cover techniques such as dimensional analysis and numerical methods (Monte Carlo simulations), and encourage students to collaborate in using these tools to solve problems in modern research.