Grant: Discovery Grants Program - Individual

This proposal describes two complementary programs that explore the novel electronic properties that emerge in certain materials when they are created with nanometer-scale structure. Our work is based on mathematical modeling using the tools of theoretical physics. The two programs explore the physics of conducting ferroelectric domain walls, and of inhomogeneous superconductors. Modern technology---computers, cell phones, medical equipment---is possible because of a decades-long push towards making smaller and faster electronic devices. Ferroelectrics make up a class of materials that hold a lot of promise for future nanoelectronic applications. Already, ferroelectric-based computer memory (FeRAM)is used commercially in applications where low power consumption or non-volatility (i.e. the memory is not lost if the power is turned off) are important. My first research program explores the science of ferroelectrics, with an eye to identifying novel features of these materials that might be useful for technological or scientific applications in the future. I am especially interested in so-called "conducting domain walls", which hold promise as core elements of writeable electronics. Writeable electronics are materials in which nanoscale circuits can be written---for example with an atomic force microscope---erased, and re-written. My second program explores the science of unconventional superconductors, and in particular how these materials behave in highly inhomogeneous environments. This work is motivated by certain families of superconductor that have attractive properties, but are also highly inhomogeneous. The conventional "BCS" theory of superconductivity is questionable in this limit, and my goal is to develop a framework to understand their microscopic physics. This program is entirely curiosity-driven. The research questions asked by my group are fundamental. What causes conducting domain walls to behave as they do? Can we develop a predictive mathematical model that describes how unconventional superconductors behave in highly inhomogeneous environments? As theoretical physicists, we seek to provide guidance for the experimental groups who design and grow the materials. We help explain confounding results of previous experiments, and aim to propose materials or devices that will exhibit new functionality.