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

非技术摘要：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。这个项目研究的是那些与周围环境没有达到热平衡的物体的现象，比如一个想象中的永远保持热的咖啡杯。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。这个项目的一个重要组成部分是教育和推广工作，以解决阻碍妇女和少数民族充分参与科学研究的“管道泄漏”问题。PI在夏季为初高中学生开设为期一周的实验物理互动式课程，并在学年期间开设讲习班，旨在点燃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：本课题的研究目的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同的概率对所有可能的构型进行抽样，从而导致热力学平衡。在一种被称为多体定位的奇怪现象中，这种假设被打破了，系统中的无序阻止了热化，即使在粒子间相互作用存在的情况下也是如此。定域态的另一个不同寻常的标志是时间晶体相的出现。就像传统晶体自发地打破空间平移对称性一样，时间晶体也可以打破时间平移对称性。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下去。多体定位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。固态材料中局部化和时间晶体的证据仍然难以捉摸。该项目的具体目标包括在门定义量子点阵列中使用自旋链来探索凝聚态系统中的多体定位和时间晶体，并揭示它们的相图。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.