Mechanical Quantum Resonators: Quantum Optics with Phonons

* 非技术性摘要 *：量子力学控制着氢原子和电子等原子尺度的小系统的行为，而要证明量子力学对更大尺度系统的适用性，尤其是那些拥有数百万或更多独立原子的系统，是一项挑战，因为需要将感兴趣的系统与周围的环境隔离开来，而这种环境破坏了我们经典经验中特有的量子效应。到目前为止，还没有在大型系统中进行明确的量子效应演示，当然不是在大型机械系统中。该项目将专注于建造小型机械谐振器，类似于用于计算机电路计时的石英晶体，与世界其他地方充分断开，以允许以明确的方式显示量子效应。特别是，振动能的量子性质，这是预测变化的步骤，而不是在一个连续的方式，将详细探讨。该多学科项目整合了研究和教育，以培养学生和博士后研究人员掌握解决物理学中这一关键问题所需的现代方法，该方法将与工程和纳米技术相结合，以实现这里提出的目标。获得的跨学科技能，其中包括最先进的纳米纤维和射频和微波技术，为学员在国家实验室，国家实验室和工业的职业生涯做好准备。技术摘要 *：该项目将研究低温、单声子量子体系中的机械谐振器。该研究将集中在一种新型的高品质因数，GHz频率的压电谐振器，它可以在这个频段有一个前所未有的品质因数。共振器的量子力学性质，特别是在单声子制度，将探讨约瑟夫森结电路最近开发的超导量子计算的应用。耦合到一个或多个约瑟夫森结的谐振器提供了一个美丽的固态模拟腔量子电动力学，这个项目将探索各种量子光学现象与相干声子。该项目的目标是揭示谐振器的弛豫时间和相干时间的值，允许第一次连接到经典品质因子;演示“量子制冷”，从多声子占据的谐振器中去除单个声子;并追求由约瑟夫森结量子比特控制的压缩效应。这将包括量子力学在宏观力学系统中的首次演示，以及量子物理学的里程碑。该多学科项目整合了研究和教育，以培养学生和博士后研究人员掌握解决物理学中这一关键问题所需的现代方法，该方法将与工程和纳米技术相结合，以实现这里提出的目标。

****NON-TECHNICAL ABSTRACT****:Quantum mechanics controls the behavior of very small, atomic-scale systems like the hydrogen atom and the electron. Demonstrations of the applicability of quantum mechanics to larger scale systems, especially ones with millions or more independent atoms, are challenging due to the need to isolate the system of interest from the environment that surrounds them, an environment that demolishes the quantum effects so peculiar to our classical experience. To date, no clear demonstration of quantum effects in large systems has been performed, certainly not in large mechanical systems. This project will focus on the construction of small mechanical resonators, similar to quartz crystals used to time computer circuits, sufficiently disconnected from the rest of the world to allow quantum effects to be displayed in an unambiguous fashion. In particular, the quantum nature of vibrational energy, which is predicted to change in steps rather than in a continuous fashion, will be explored in detail. The multidisciplinary project integrates research and education in order to train students and postdoctoral researchers in modern methods required to address this key problem in physics, which will be integrated with engineering and nanotechnology to achieve the goals set forward here. The acquired interdisciplinary skills, which include state-of-the-art nanofabrication and radiofrequency and microwave technology, prepare the trainees for careers in academe, national laboratories, and industry.****TECHNICAL ABSTRACT****:This project will investigate mechanical resonators in the low-temperature, single-phonon quantum regime. The study will focus on a novel type of high quality factor, GHz frequency piezoelectric resonator, which can have an unprecedented quality factor in this frequency band. The quantum mechanical properties of the resonators, especially in the single-phonon regime, will be probed by Josephson junction circuits recently developed for applications to superconducting quantum computation. A resonator coupled to one or more Josephson junctions provides a beautiful solid-state analog to cavity quantum electrodynamics, and this project will explore a variety of quantum optical phenomena with the coherent phonons. The goals of the project are to reveal values for the relaxation time and the coherence time of the resonator, allowing a first connection to the classical quality factor; to demonstrate "quantum refrigeration", removing individual phonons from a resonator with multi-phonon occupation; and to pursue squeezing effects controlled by the Josephson junction qubit. This would comprise the first demonstration of quantum mechanics in a macroscopic mechanical system, and a milestone in quantum physics. The multidisciplinary project integrates research and education in order to train students and postdoctoral researchers in modern methods required to address this key problem in physics, which will be integrated with engineering and nanotechnology to achieve the goals set forward here.