CAREER: Quantum Acoustic Information Processing with Phononic Crystal Devices

我们充分理解自然界的量子定律，足以写出描述复杂分子、奇异材料和电子设备等现实世界系统行为的方程。然而，在大多数情况下，在计算机上计算这些方程的解以做出具体的预测仍然是不可能的。最近，物理学家开发了一种不同的计算方法，可以利用量子物理定律固有的巨大复杂性来预测自然。如果能够建造这样的量子计算机，它们还将执行强大的量子算法，这些算法可以破译密码，解决优化问题，并模拟目前难以处理的量子化学系统。实现有用的量子机仍然是一个遥不可及的梦想。在过去的十年里，一种涉及超导材料制成的微波频率电路和系统的方法已经成为实现量子机的主要候选方案。这些系统使用微波频率光或光子之间的相互作用来编码、处理和存储量子信息。我们建议对这种方法进行改进，使用微波频率的声音或声子。如果成功，我们的方法将显著降低量子机器的复杂性，并能够快速扩展到更大的量子计算机。提高这些量子计算机的处理能力预计将对从基础科学到药物发现等许多应用领域的科学和技术产生重大影响。为了产生进一步的影响，我们提议的计划包括一个专业教育推广部分，将为希望进入量子科学和工程领域的工程师开发和提供课程。拟议中的计划将提供一套有针对性的四门课程，专门为执业工程师量身定做，这些课程将培养成为量子科学家所需的理论和实践技能。新兴的量子机使用光子之间的相互作用，即单量子电磁激发，来编码、处理和存储量子信息。我们提出了对这种方法的改进，除了光子之外，还使用声子，即振动的量子，来实现量子功能。所提出的声子装置比目前量子计算方法中使用的电路元件小几千倍，因为声速比光速低得多。此外，声子设备可以非常相干，相干性是竞争对手光子系统的几千倍。这些特性支持极大地促进扩展到更大系统规模的新架构。为了研究这种方法的可行性，我们将制造包含超导跨声子量子比特和机械谐振器的芯片，并在这些元素之间执行量子门。我们还将开发使用量子声学设备作为高效多路复用和路由量子信号的方法。将机械设备和超导量子比特结合在一起的拟议架构的成功展示极大地加速了量子机器的发展。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

We understand the quantum laws of nature well enough to write equations that describe the behavior of real-world systems such as complex molecules, exotic materials, and electronic devices. However, in the majority of cases, computing the solutions of these equations on a computer to make concrete predictions remains outside the realm of possibilities. Recently, physicists have developed a different approach to computation that could harness the enormous complexity inherent in the laws of quantum physics to make predictions about nature. Such quantum computers, if they can be built, would also execute powerful quantum algorithms that break cryptographic codes, solve optimization problems, and simulate currently intractable systems in quantum chemistry. Realizing a useful quantum machine remains an elusive dream. In the last decade, an approach involving microwave frequency circuits and systems made from superconducting materials has emerged as a leading candidate for realizing a quantum machine. These systems use the interactions between microwave frequency light, or photons, to encode, process, and store quantum information. We propose an enhancement of this approach that uses microwave-frequency sound, or phonons. If successful, our approach will significantly reduce the complexity of a quantum machine and enable rapid scaling to larger quantum computers. Improving the processing power of these quantum computers is expected to significantly impact science and technology in many application spaces ranging from basic science to drug discovery. For further impact, our proposed program includes a professional education outreach component that will develop and deliver a curriculum to engineers who hope to move into quantum science and engineering. The proposed program will deliver a targeted set of four courses tailored to practicing engineers that will build the theoretical and practical skills needed to become quantum scientists.Emerging quantum machines use the interactions between photons, single quanta of electromagnetic excitation, to encode, process, and store quantum information. We propose an enhancement of this approach that in addition to photons, uses phonons, the quanta of vibrations, to realize quantum functionality. The proposed phonon devices are many thousands of times smaller than the circuit elements used in current approaches to quantum computing because the speed of sound is considerably lower than the speed of light. Additionally, phonon devices can be remarkably coherent, with the coherence times many thousands of times longer than competing photonic systems. These properties enable new architectures that greatly facilitate scaling to larger system sizes. To investigate the feasibility of this approach, we will fabricate chips that contain superconducting transmon qubits and mechanical resonators, and we will perform quantum gates between these elements. We will also develop ways of using quantum acoustic devices as a means of efficiently multiplexing and routing quantum signals. Successful demonstration of the proposed architecture bringing together mechanical devices and superconducting qubits significantly accelerates the development of quantum machines.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.