Light Control of Superconductivity by Subcycle Dynamic Symmetry Breaking

点击翻译按钮获取中文摘要

Non-technical abstract: Scientists and engineers have recently come to realize that certain materials, such as superconductors, have properties that can be exploited for applications in quantum information and energy science, e.g., processing, recording, storage and communication. Light can be used to create and control superconductivity. This makes it possible to design exotic properties in superconductors which can then be used in making devices for computing, sensing and communication. The proposed project aims to study one group of these materials called iron pnictide superconductors. These materials will be rapidly perturbed by laser light and their responses recorded using high speed measurements. The goal is to extract details of superconductivity in these materials so that they can be utilized in making devices for quantum information and energy applications. Education is an integral and essential component in this proposal. Specific plans have been made to mentor college professors/undergraduates, to engage high school teachers and their students through "A Physics Day" program; and to provide research and training opportunities for underrepresented minority students. Technical abstract: A grand challenge underlying the implementation of superconducting electronics and its quantum information applications is how to establish universal quantum control principles for switching coherent orders and modulating supercurrents at faster-than-terahertz clock rates with nearly "zero-heat" energy dissipation. The project aims to demonstrate the feasibility of harnessing light-driven coherence and nonlinearity to probe and control quantum phases and collective modes in specifically-chosen iron pnictide superconductors. Specifically we will implement a subcycle dynamic symmetry breaking principle using a tailored light pulse to nonthermally modulate correlation gaps and/or periodically bias supercurrents. The research goals are: (1) explore the laser-driven superconducting systems with different magnetic orders and fluctuations, clean vs. dirty limit, different paring symmetries; (2) Reveal collective modes via light-induced supercurrents; (3) Achieve proof-of-concept validation of coherent control of superconducting orders using "tailored" laser pulse trains. Understanding how to measure, manipulate and harvest coherence and entanglement in superconductors with unprecedented ultrafast visualization can potentially break new grounds for materials discovery - to achieve room temperature superconductivity transiently, increase the coherence times, and stabilize the transient phases beyond technologically-relevant, many nanosecond timescales. Reaching such a fundamental understanding and implementing dynamical quantum switching will advance Quantum Leap, one of the 10 Big Ideas of the National Science Foundation.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.