NSF-BSF: High-Temperature Superconducting Photon Detectors

该提议旨在通过发展基于高温超导体(HIGH-TC)的超导纳米线光子探测器来实现实际应用中的量子有限光子灵敏度。到目前为止，这种灵敏度是通过在极低温度下工作的标准超导体实现的。尽管如此，这种传感器提供了量子通信、化学探测和微光成像所需的终极灵敏度。高T_c铜酸盐可以达到高于液氮的性能，为此类设备的实用化带来了一场革命。虽然这些材料已经被研究了几十年，但它们对制造设备的典型方法非常敏感。通过Alex Hayat(Technion)和Kenneth Burch(波士顿学院-BC)团队的合作，将研究和克服制造此类设备的基本限制。具体地说，他们将利用这些材料薄膜生长的最新进展，单原子层石墨烯作为保护层，并在惰性气氛中制备，以揭示材料退化的根源，以及保护高T_c的方法，用于制造光学传感器。此外，这项努力将使一系列不同的受训人员接触到切割制造和光学技术，以及量子通信前沿的主题。多年来，人们对高T_c铜酸盐进行了广泛的研究，重点是对其磁性、奇怪的金属和超导响应的潜在机制的研究。此外，大量的努力集中在使用铜氧化物进行低损耗的电力传输上。相反，该项目将重点放在将这些材料纳入光电子器件和量子光学实验的根本挑战上。具体地说，该团队将研究为选择性区域生长YBCO薄膜准备模板的新方法。他们还将探索使用CVD石墨烯作为薄膜的保护层，以将制造过程中的损害降至最低。两者都将涉及使用手套盒中的无尘室，以将大气污染降至最低。除了标准的电子束光刻，还将尝试热扫描光刻以减少不必要的损害。最终得到的薄膜和器件将通过一系列技术(EDX、拉曼、原子力显微镜、透射电子显微镜)进行表征，以揭示限制性能的机制。此外，还将测量量子探测器的属性，以揭示控制量子有限光子灵敏度性能的关键参数。这一奖项反映了NSF的法定使命，并已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。

This proposal aims to enable quantum limited photon sensitivity in practical applications by developing superconducting nanowire photon detectors based on high-temperature superconductors (high-Tc). To date such sensitivity is achieved with standard superconductors operating at extremely cold temperatures. Nonetheless such sensors offer the ultimate sensitivity needed in quantum communications, chemical detection, and low light imaging. High-Tc cuprates could achieve such performance above liquid nitrogen, offering a revolution in the practicality of such devices. While these materials have been studied for decades, they are quite sensitive to the typical approaches to making devices. The fundamental limitations in making such devices will be studied and overcome via a collaboration between the groups of Alex Hayat (Technion), and the group of Kenneth Burch (Boston College-BC). Specifically, they will use recent advances in the thin film growth of these materials, single atomic layer graphene as a protective coating and fabrication in inert atmosphere to uncover the origin of material degradation and methods to protect the high Tc for fabrication into optical sensors. In addition, the effort will enable a range of diverse trainees to be exposed to cutting fabrication and optical techniques as well as topics at the forefront of quantum communications. High Tc cuprates have been extensively studied over the years, with a focus on the underlying mechanisms of their magnetic, strange metal and superconducting responses. In addition, substantial efforts have focused on using the cuprates for low loss electrical transmission. This project focuses instead on the fundamental challenges to incorporating these materials in optoelectronic devices and quantum optics experiments. Specifically, the team will investigate new methods of preparing templates for selective area growth of YBCO films. They will also explore the use of CVD graphene as a protective layer on the films to minimize damage in fabrication. Both will involve the use of a cleanroom in a glovebox to minimize atmospheric contamination. In addition to standard e-beam lithography, thermal scanning lithography will be attempted to reduce unwanted damage. Ultimately the resulting films and devices will be characterized by a range of the techniques (EDX, Raman, AFM, TEM) to uncover the mechanisms limiting performance. In addition, the quantum detector properties will be measured to reveal the key parameters governing the performance for quantum limited photon sensitivity.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.