MRI: Development of a Scanning 4-Probe Microscope for Discovery and Characterization of Quantum Materials and Devices

非技术描述量子技术发展中的一个关键挑战是理解原子尺度的材料积木(电子的电荷和自旋)与赋予设备功能的这些积木的运动之间的联系。该项目支持开发一种新型的四探针显微镜来应对这一挑战。这种新的显微镜可以独立地扫描材料或设备上的四个可切换探测器：单独的探测器可以成像静态原子、电荷和自旋，而两个或更多的探测器一起可以检测这些电荷的运动，并旋转长度从10纳米到100微米。该显微镜还可以在高磁场下工作，并将样品冷却到液氦温度--从而允许进入新的量子现象区域。这种显微镜实现的项目包括筛选新的不均匀材料，绘制单原子缺陷周围的电子流动图，开发编织聚合物电缆等纳米结构材料，从单个原子组装复杂的传感器，以及搜索可以成为新技术构建块的新兴粒子。显微镜的开发是在哈佛大学和一家小公司的合作下进行的；研究生和博士后研究人员在显微镜开发过程中接受培训，后来又在推出商业产品方面接受培训。显微镜被安置在哈佛纳米系统中心，该中心是东北许多学院、大学和工业的科学纽带。显微镜的专职工作人员为智力和人口统计学上不同的用户提供技术教育，反过来又是跨学科想法的连接点和灵感来源。技术说明这项重大研究仪器拨款支持紧凑和多功能扫描4探针显微镜(S4 PM)的开发，以促进新量子材料和器件的发现和制造。S4 PM满足了在亚埃尺度上了解材料的静态原子结构和电子波函数之间的关系，以及导致设备功能的10纳米到100微米之间的电和磁传输特性的关键需求。S4PM采用了新颖的旋转运动设计，缩小了仪器尺寸，允许在大约1Kelvin、高达5Tesla的磁场和10s的纳米传输分辨率下运行。S4 PM允许灵活地原位交换各种互补探针，包括扫描隧道显微镜、原子力显微镜、扫描栅极和扫描金刚石氮空位。S4PM的研究项目包括筛选非均匀新材料的输运性质，绘制单原子缺陷和束缚周围的电子和自旋流动图，开发编织聚合物Litz电缆等纳米结构材料，组装原子尺度的传感器(如非常小的超导量子干涉设备)，以及搜索紧急粒子，如Majorana费米子和磁单粒子。该奖项反映了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。

Non-Technical DescriptionA key challenge in quantum technology development is to understand the link between the atomic-scale building blocks or "quanta" of materials (the charges and spins of electrons) and the motion of these building blocks that give a device its function. This project supports development of a novel 4-probe microscope to address this challenge. The new microscope independently scans four switchable probes across a material or device: individual probes can image static atoms, charges, and spins, while two or more probes together can detect the motion of these charges and spins from 10s of nanometers to 100s of micrometers in length. The microscope also operates in a high magnetic field and with samples cooled to liquid helium temperature - thus allowing access to a new regime of quantum phenomena. Projects enabled by this microscope include screening of new inhomogeneous materials, mapping the flow of electrons around single atom defects, developing nanostructured materials such as braided polymer cables, assembling complex sensors from individual atoms, and searching for emergent particles that can become the building blocks of new technologies. The microscope development is carried out in collaboration between Harvard and a small company; graduate students and postdoctoral researchers are trained through the microscope development process and later, in pursuing the launch of a commercial product. The microscope is housed in Harvard's Center for Nanoscale Systems, a scientific nexus for many Northeast colleges, universities, and industries. The microscope's dedicated staff provides technical education to an intellectually and demographically diverse cadre of users, and in turn serves as a point of connection and inspiration for cross-disciplinary ideas.Technical DescriptionThis Major Research Instrumentation grant supports development of a compact and versatile scanning 4-probe microscope (S4PM), to facilitate the discovery and fabrication of novel quantum materials and devices. The S4PM meets a critical need to understand the relationship between the static atomic structure and electronic wave functions of a material at the sub-Angstrom scale, and the electrical and magnetic transport properties across 10s of nanometers to 100s of microns that lead to device functionality. The S4PM employs a novel rotary motion design that reduces instrument size and allows operation at about 1 Kelvin, up to 5 Tesla of magnetic field, and 10s of nanometer transport resolution. The S4PM allows flexible in-situ exchange of a wide variety of complementary probes including scanning tunneling microscopy, atomic force microscopy, scanning gate, and scanning diamond nitrogen-vacancy. Research projects enabled by this S4PM include screening the transport properties of inhomogeneous new materials, mapping electron and spin flow around single atom defects and constrictions, developing nanostructured materials such as braided polymer Litz cables, assembling atomic-scale sensors such as a very small superconducting quantum interference device, and searching for emergent particles such as Majorana fermions and magnetic monopoles.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.