CAREER: Circuit Quantum Optics with Piezoelectric Surface Acoustic Waves

混合量子系统和技术表现出令人兴奋的特性和新颖的功能，可以通过将具有根本不同但互补的特性的量子电路和器件结合在一起来创建。对于基于超导量子比特(量子比特)耦合到压电声表面波(SAW)器件的混合系统尤其如此。这些工程化系统，其中存储在量子比特中的量子信息可以可控地耦合到压电晶体的微观表面波，是理解强耦合合成量子系统奇异行为的理想平台。此外，声表面波器件已经是许多经典电子设备的关键部件，如手机、触摸屏和化学传感器。鉴于它们在经典电子学中的广泛适用性，人们很自然地会问，基于声表面波的设备是否会在量子信息科学(QIS)领域获得类似的成功。为量子应用开发压电声表面波器件还处于初级阶段，许多未知领域已经成熟，可以开发新技术和令人兴奋的发现。通过利用超导量子比特的受控量子行为，拟议的计划将研究基于声表面波的量子系统的基本性质，并推动下一代量子传感、计算和通信技术的发展。该计划还将促进不同研究生群体的教育和研究经验，并加强首席研究员(PI)在密歇根州立大学(MSU)正在开发的QIS教育倡议。作为密歇根州立大学量子计算、科学和工程中心的副主任，该协会还致力于提高密歇根州立大学量子信息系统研究人员的多样性，帮助从代表性不足的群体中招聘研究生和本科生，并为该中心的初级量子信息系统研究人员寻找本地研究机会和私营部门实习机会提供支持。该计划专注于使用由超导电路量子比特和压电表面声波(SAW)器件组成的混合量子系统对电路量子光学的新机制进行实验研究。这些项目涵盖了从量子声学浴工程到高频声表面波压声子压缩状态的产生等新课题。耦合到精确设计的声表面波谐振器的Transmon量子比特将利用可控制的声耗散水平来自主稳定相干量子比特叠加，并通过声音损失来设计奇异的量子态。此外，声表面波的非经典状态将利用参数约瑟夫森结器件从微波光子的非经典状态转换，从而创造了研究与超导量子比特耦合的巡回压电声子的非马尔科夫性质的机会。该计划还将探索开发超越跨子的量子比特的基于声表面波的新型器件的可能性(即通过结合通量量子比特或基于磁通的器件)。这些“量子声学”系统和装置的实现和理解将极大地扩展高度受控的合成量子系统的基础知识，以及它们如何实现新的量子技术。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。

Hybrid quantum systems and technologies exhibiting exciting properties and novel functionality can be created by bringing together quantum circuits and devices with fundamentally different, but complementary, properties. This is particularly true of hybrid systems based on superconducting quantum bits (qubits) coupled to piezoelectric surface acoustic wave (SAW) devices. These engineered systems, in which quantum information stored in the qubit can be controllably coupled to the microscopic surface waves of a piezoelectric crystal, are an ideal platform for understanding the exotic behavior of strongly-coupled synthetic quantum systems. Additionally, SAW devices are already a key component in many classical electronic devices such as cell phones, touch screens and chemical sensors. Given their wide applicability in classical electronics it is natural to ask if SAW-based devices might find similar success in the field of quantum information science (QIS). Developing piezoelectric SAW-devices for quantum applications is in its infancy, with much uncharted territory ripe for the development of new technologies and exciting discoveries. By harnessing the controlled quantum behavior of superconducting qubits, the proposed program will investigate the fundamental properties of SAW-based quantum systems and advance the development of next-generation technologies for quantum sensing, computation and communication. The program will also advance the education and research experiences of a diverse group of graduate students and strengthen the QIS educational initiatives that the principal investigator (PI) is developing at Michigan State University (MSU). As the Associate Director of the MSU Center for Quantum Computing, Science and Engineering the PI is also working to enhance the diversity of QIS researchers at MSU by helping to recruit graduate and undergraduate students from under-represented groups and provide support to find local research opportunities and private sector internships for the Center’s junior QIS researchers.This program is focused on the experimental investigation of novel regimes of circuit quantum optics using hybrid quantum systems composed of superconducting circuit-based qubits coupled to piezoelectric surface acoustic wave (SAW) devices. The projects cover new topics ranging from quantum acoustic bath engineering to the generation of squeezed states of high-frequency SAW piezo-phonons. Transmon qubits coupled to precisely designed SAW-resonators will leverage controllable levels of acoustic dissipation to autonomously stabilize coherent qubit superpositions and engineer exotic quantum states via acoustic loss. Additionally non-classical states of SAWs will be transduced from non-classical states of microwave photons using parametric Josephson junction devices, creating the opportunity to investigate non-Markovian properties of itinerant piezo-phonons coupled to superconducting qubits. The program will also explore the possibility of developing novel SAW-based devices with qubits beyond transmons (i.e. via the incorporation of flux-qubits or fluxonium-based devices). The realization and understanding of these “quantum acoustic” systems and devices will greatly expand the fundamental knowledge of highly-controlled synthetic quantum systems and how they might realize new quantum technologies.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.