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

量子计算和技术有望改变社会和商业。然而，今天存在的量子计算机尚未实现这一承诺，这在很大程度上是因为它们的关键组件-量子比特或量子比特-太容易出错。早期的数字计算机也有不可靠的组件，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现在使用的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”量子比特可以加速解决社会利益问题所需的大规模，强大的量子计算机的发展。此外，该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一个博尔德-丹佛地区量子社区会议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分享。这个CAREER提案将为新型超低误差量子比特奠定理论基础。这些第二代量子比特可以改变量子技术的格局，因为低错误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态的量子比特错误方面已经取得了显着的进展，但这些第一代量子比特被设计为仅低于实现容错量子纠错所需的错误率。第二代量子比特发展的一个指导原则是：量子比特应该被构造成使得物理定律提供对某些错误的免疫力。这项CAREER提案将在超导电路中使用这一原理来开发第二代量子比特。该项目的主要目标是（1）为第二代量子比特（称为0-π量子比特）开发双量子比特门，（2）设计一类新的超保护第二代量子比特- cos（Nπ）量子比特，以及（3）为第二代量子比特开发错误保护门。所提出的设计将通过噪声模型的仿真来验证。为了确定拟议的量子比特和门是否具有上级性能，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NSF的法定使命，并通过使用基金会的智力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.