CAREER: Second Generation Qubits -- the future of superconducting quantum computing

量子计算和技术将改变社会和商业。然而，目前存在的量子计算机还没有实现这一承诺，很大程度上是因为它们的关键组件——量子比特或量子位——太容易出错。早期的数字计算机也受到元件不可靠的困扰，但随着时间的推移，晶体管等新技术使今天的计算机更便宜、更小、更可靠。总的来说，这个CAREER项目的目标是通过设计比目前使用的量子比特更可靠的量子比特来刺激量子技术的类似发展。这些低误差的“第二代”量子比特可以加速大规模、强大的量子计算机的发展，这些计算机需要解决社会感兴趣的问题。此外，这个CAREER项目旨在增加公众对量子技术的参与，并扩大跨学科科学家和工程师接受量子教育的机会。这些目标将通过建立博尔德-丹佛地区量子社区聚会和开发一个公开的量子入门课程来实现，该课程将与其他教育工作者共享。该CAREER提案将为新型超低误差量子位发展理论基础。这些第二代量子比特可能会改变量子技术的格局，因为低误差量子比特是实现量子计算前景的关键因素。虽然在减少跨硬件模式的量子比特错误方面已经取得了显着进展，但这些第一代量子比特的设计性能刚好低于实现容错量子纠错所需的错误率。开发第二代量子比特的指导原则是：量子比特的构造应该使物理定律免于某些错误。这项CAREER提案将在超导电路中利用这一原理开发第二代量子比特。该项目的主要目标是(1)为第二代量子位开发称为0 - π量子位的两个量子位门，(2)设计一类新的超保护第二代量子位- cos（N变量）量子位，以及(3)为第二代量子位开发错误保护门。提出的设计将通过噪声模型的仿真来验证。为了确定所提出的量子比特和门是否具有优越的性能，将通过将它们与最成功的超导量子比特：transmon进行比较来评估它们的性能。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。

Quantum computing and technology are poised to transform society and business. However, the quantum computers that exist today have yet to live up to this promise, in large part because their key component –the quantum bit or qubit – is too prone to errors. Early digital computers also suffered from unreliable components, but over time new technologies such as the transistor have made today’s computers cheaper, smaller, and more reliable. Broadly, the goal of this CAREER project is to spur on similar developments in quantum technologies by designing qubits that are significantly more reliable than those used today. These low-error “Second Generation” qubits could accelerate the development of the large-scale, robust quantum computers needed to solve problems of societal interest. Additionally, this CAREER project seeks to increase public engagement with quantum technology and to broaden access to quantum education for scientists and engineers across disciplines. These aims will be met through establishing a Boulder-Denver area quantum community meetup and by developing a publicly-available introductory quantum course that will be shared with other educators.This CAREER proposal will develop theoretical foundations for novel types of ultra-low error qubits. These Second Generation qubits could transform the landscape of quantum technology, as low error qubits are critical ingredients for realizing the promise of quantum computation. While remarkable progress has already been made on reducing qubit errors across hardware modalities, these first-generation qubits are designed to perform just below the required error rate for implementing fault-tolerant quantum error correction. A guiding principle in the development of second generation qubits is: the qubit should be constructed so that the physical laws provide immunity from certain errors. This CAREER proposal will pursue the development of second generation qubits using this principle in superconducting circuits. The major objectives of the project are to (1) develop two-qubit gates for a second generation qubit called the 0–π qubit, (2) design a new class of ultra protected second generation qubits – cos(N𝜑) qubits, and (3) develop error protected gates for second generation qubits. The designs proposed will be validated by simulation with noise models. To determine whether the proposed qubits and gate have superior performance, their performance will be evaluated by comparing them to the most successful superconducting qubit: the transmon.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.