近日，美国耶鲁大学Hong X.Tang及其研究团队取得一项新进展。经过不懈努力，他们实现从单通量量子电路到室温的光子链路。相关研究成果已于2024年1月16日在国际知名学术期刊《自然—光子学》上发表。
该研究团队演示了快速单通量量子电路的第一个直接光学读出之一，而无需额外的电放大，这是由一种新型超导电光调制器实现的，该调制器在1米长的超导电光调制器上具有创纪录的42mV的低半波电压Vπ。利用超导体的低欧姆损耗，研究人员打破了基本的vπ带宽权衡，并展示了在低温下0.2米长的超导电光调制器上高达17GHz的电光带宽。这项研究工作为未来大规模超导电路和室温电子器件之间的高带宽信号传输提供了可行的解决方案。
据悉，在超导量子和经典逻辑电路中，低温和室温环境之间的宽带、节能信号传输一直是一个主要的瓶颈。光子链路有望通过同时提供高带宽和低热负载来克服这一挑战。然而，低温电光调制器的发展一直受到超导电路严格要求的制约。例如，快速单通量量子电路的信号幅度很小，只有几毫伏，远低于传统电路中使用的电压信号。
附：英文原文
Title: Photonic link from single-flux-quantum circuits to room temperature
Author: Shen, Mohan, Xie, Jiacheng, Xu, Yuntao, Wang, Sihao, Cheng, Risheng, Fu, Wei, Zhou, Yiyu, Tang, Hong X.
Issue&Volume: 2024-01-16
Abstract: Broadband, energy-efficient signal transfer between a cryogenic and room-temperature environment has been a major bottleneck for superconducting quantum and classical logic circuits. Photonic links promise to overcome this challenge by offering simultaneous high bandwidth and low thermal load. However, the development of cryogenic electro-optic modulators—a key component for the photonic readout of electrical signals—has been stifled by the stringent requirements of superconducting circuits. Rapid single-flux-quantum circuits, for example, operate with a tiny signal amplitude of only a few millivolts, far below the volt-level signal used in conventional circuits. Here we demonstrate one of the first direct optical readouts of a rapid single-flux-quantum circuit without additional electrical amplification enabled by a novel superconducting electro-optic modulator featuring a record-low half-wave voltage Vπ of 42mV on a 1-m-long superconducting electro-optic modulator. Leveraging the low ohmic loss of superconductors, we break the fundamental Vπ–bandwidth trade-off and demonstrate an electro-optic bandwidth up to 17GHz on a 0.2-m-long superconducting electro-optic modulator at cryogenic temperatures. Our work presents a viable solution towards high-bandwidth signal transfer between future large-scale superconducting circuits and room-temperature electronics.
DOI: 10.1038/s41566-023-01370-2
Source: https://www.nature.com/articles/s41566-023-01370-2