CAREER: Quantum Spin-Optomechanics of Optically Levitated Nanodiamonds

职业：光悬浮纳米金刚石的量子自旋光力学

• 批准号: 1555035
• 负责人: Tongcang Li
• 金额: $ 45.78万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1555035&HistoricalAwards=false
• 关键词: CAREER; Quantum; Spin; Optomechanics; Optically

Very small particles can behave in ways that are contrary to common sense. For example, an electron (one of the particles that make up atoms) can be at multiple locations at the same time and can tunnel through a barrier--something forbidden by the classical laws of physics. The theory that explains these counterintuitive behaviors of small particles is "quantum mechanics". This CAREER project will investigate the possibility of making quantum mechanics appear manifest in larger, more macroscopic, systems. In specific, the project will investigate how to couple the spin of an electron to the motion of a nanoparticle (containing millions of atoms). The nanoparticle will be levitated by a laser beam in vacuum to avoid perturbations from the environment. This system should serve as a very sensitive force detector with many applications. It may enable other experiments to study the conflict between general relativity and quantum mechanics, a longstanding problem in physics. The research will be integrated with several related educational activities, including direct training of graduate and undergraduate students participating in the research, and conducting inquiry workshops about infrared light for middle and high school teachers and students. Infrared light is not visible to human eyes, but plays a crucial role in global warming and fiber-optic communication. In the present work, infrared light will be used to levitate nanoparticles in vacuum. After doing hands-on experiments with infrared light in the workshop, teachers will be able to take their apparatus for use in their classrooms.In more technical detail, this research project will develop a system that combines the advantages of both trapped atoms and conventional optomechanical systems for studying macroscopic quantum mechanics: an optically levitated nanodiamond with a built-in nitrogen-vacancy (NV) center. In some ways, this system can be considered to be an "artificial atom" with a very large mass. The electron spin of the NV center can be coupled to the motion of the nanodiamond with a magnetic field gradient. This coupling can be used to create large quantum spatial superposition states of the nanodiamond, which will lead to the development of a nanoparticle matter-wave interferometer for fundamental tests of quantum mechanics in unexplored parameter regimes. The main focus of this CAREER project will be to experimentally study the coupling between an NV electron spin and both the center-of-mass motion and the rotation of an optically levitated nanodiamond. The motion of the levitated nanodiamond will be cooled to near quantum ground state by active feedback cooling. The NV electron spin will be used to sense and manipulate the motion of the nanodiamond. It will also be used to measure the internal temperature of the levitated nanodiamond which affects the quantum coherence time.

很小的粒子可以以与常识相反的方式行为。例如，电子（构成原子的颗粒之一）可以同时在多个位置，并且可以穿过障碍物的隧道，这是物理学定律所禁止的。解释这些小颗粒的这些违反直觉行为的理论是“量子力学”。该职业项目将调查使量子力学显现出现在更大，更宏观的系统中的可能性。 在特定的情况下，该项目将研究如何将电子的自旋与纳米颗粒的运动（包含数百万个原子）的运动。纳米颗粒将通过真空中的激光束悬浮，以避免对环境的扰动。该系统应作为具有许多应用的非常敏感的力检测器。 它可能使其他实验能够研究一般相对论与量子力学之间的冲突，这是物理学长期存在的问题。这项研究将与几项相关的教育活动集成，包括对研究生的直接培训和参加研究的本科生，以及为中学和高中教师和学生提供有关红外光线的询问讲习班。红外线对人眼看不到，而是在全球变暖和光纤传播中起着至关重要的作用。 在目前的工作中，红外光将用于真空中的纳米颗粒。在研讨会中对红外光进行动手实验之后，教师将能够将其设备用于课堂上。在更具技术细节中，该研究项目将开发一个系统，结合了原子和传统光学机械系统的优势，用于研究巨型量子机制：与内置的nanodiamond nitr nitr nitr nitr nitr nitr。在某些方面，该系统可以被认为是具有很大质量的“人造原子”。 NV中心的电子自旋可以与磁场梯度的纳米原子座的运动耦合。该耦合可用于创建纳米座的大量子空间叠加态，这将导致开发纳米颗粒物质波 - 波波干涉仪，以在未开发的参数方面进行量子力学的基本测试。该职业项目的主要重点是实验研究NV电子旋转与质量运动中心运动和光学浮动纳米座的旋转之间的耦合。通过主动反馈冷却，悬浮的纳米座的运动将被冷却至近量子基态。 NV电子旋转将用于感知和操纵纳米座的运动。它也将用于测量影响量子相干时间的悬浮纳米座的内部温度。