CAREER: Non-Equilibrium Quantum Physics in Solid-State Spin Chains

统计力学和热力学是几乎所有科学领域的基础，包括生物学，化学和物理学。这个项目研究的是与周围环境不达到热平衡的物体中的现象，比如一个永远保持热的想象中的咖啡杯。对这些系统的研究很重要，可能在高温超导和量子计算等领域有不同的应用。该项目的一个重要组成部分是开展教育和外联工作，以解决阻碍妇女和少数群体充分参与科学研究的“渗漏管道”问题。PI正在为初中和高中学生开发为期一周的实验物理学互动课程，并在学年期间举办研讨会，旨在激发下一代科学家对实验研究的热情。PI还为本科生开发了一门量子技术课程，并指导本科生和研究生学习最先进的量子纳米技术。技术摘要：本项目的研究目标是研究量子点自旋链中的非平衡量子物理。统计力学的基本假设是，一个物理系统将以相等的概率对每一种可能的构型进行采样，从而达到热力学平衡。在一种被称为多体定域化的奇异现象中，这种假设被打破了，系统中的无序阻止了热化，即使存在粒子间的相互作用。局域态的另一个不寻常的标志是时间晶体相的出现。就像传统晶体会自发地破坏空间平移对称性一样，时间晶体也能破坏时间平移对称性。在时间晶体中，系统对周期性驱动的次谐波响应无限期地持续。多体定域和时间晶体挑战了我们对统计力学和热力学的理解，并将证明量子信息处理的宝贵资源。 在固态材料中，局域化和时间晶体的证据仍然难以捉摸。该项目的具体目标是利用门定义量子点阵列中的自旋链来探索凝聚态系统中的多体局域化和时间晶体，并揭示它们的相图。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical abstract: Statistical mechanics and thermodynamics underlie nearly all fields of science, including biology, chemistry, and physics. This project studies phenomena in objects that do not reach thermal equilibrium with their surroundings, such as an imaginary coffee cup that stays hot forever. The study of these systems is important and may have diverse applications in fields like high-temperature superconductivity and quantum computing. A significant component of this project involves education and outreach efforts to address the “leaky pipeline,” which prevents women and minorities from full involvement in scientific research. The PI is developing interactive, week-long courses in experimental physics for middle- and high-school students during the summer and workshops during the school year designed to ignite a passion for experimental research in the next generation of scientists. The PI is also developing a quantum technology course for undergraduates and is mentoring undergraduate and graduate students in state-of-the-art quantum nanotechnology.Technical abstract: The research objective of this project is to investigate non-equilibrium quantum physics in quantum-dot spin chains. The fundamental postulate of statistical mechanics is that a physical system will sample every possible configuration available to it with equal probability, leading to thermodynamic equilibrium. In a bizarre phenomenon called many-body localization, this assumption breaks down, and disorder in the system prevents thermalization, even in the presence of inter-particle interactions. Another unusual hallmark of localized states is the appearance of time-crystal phases. Just as conventional crystals spontaneously break spatial translation symmetry, time crystals can break time-translation symmetry. In time crystals, a subharmonic response of the system to a periodic drive persists indefinitely. Many-body localization and time-crystals challenge our understanding of statistical mechanics and thermodynamics and will prove valuable resources for quantum information processing. Evidence of localization and time-crystals in solid-state materials remains elusive. The specific objectives of this project involve using spin chains in gate-defined quantum-dot arrays to explore many-body localization and time-crystals in condensed matter systems and uncover their phase diagrams.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.