Princeton Center for Complex Materials

* 非技术摘要 * 普林斯顿大学MRSEC的跨学科研究集中在材料研究的三个方向。第一个是利用物理学和化学的最新进展来揭示半导体中电子的新的“拓扑”量子特性。这项研究有望使未来的电子产品具有超低的散热能力，并使量子计算的新方法成为可能。在第二个方向，研究人员将联合收割机与两种新技术相结合，使非常薄的聚合物薄膜的生长具有对许多行业应用至关重要的特殊物理特性。第三个方向试图控制和操纵被困在纳米线中的单个电子的自旋。这些进展将导致量子计算的逻辑元件以及一类新的广泛可调谐激光器。研究人员参与了广泛的教育项目。每年夏天，从全国400多名申请者中选出20名本科生，从事监督研究，为科学和工程研究生院做准备。此外，研究人员还接待了来自特伦顿中央高中的18名高中生和30名中学生，参加为期3周的严格的科学夏令营。该校校友的高中毕业率达到100%，其中大多数人继续上大学。此外，研究人员每年举办8次为期一天的科学博览会（其中一些与镇图书馆联合举办），吸引了300至800名K-12学生及其家长到校园。* 技术摘要 * 在3个项目中的第一个项目中，研究人员试图扩大对绝缘体，半导体和半金属中电子的新拓扑量子特性的研究。目前，由于布洛赫理论中忽略了拓扑学原理，建立已久的晶体固体布洛赫理论正在进行修正。能隙被“反转”（相对于原子极限）的半导体表现出被无质量狄拉克费米子占据的表面态。利用扫描隧道显微镜、传输和光电发射实验，研究人员将测试新视角的关键预测，并寻找新的拓扑相和激发（例如马约拉纳费米子）。在第二个项目中，研究人员将应用一种名为MAPLE的激光烧蚀技术来生长和研究在新的条件下沉积的聚合物薄膜，这些条件可以显著提高玻璃化转变温度。结合荧光，纳米成像和模拟方面的专业知识，他们将解决技术上的重要问题，为什么受限聚合物的热力学性质（例如玻璃化转变）与散装聚合物的热力学性质有显着差异。第三个项目的研究人员将解决量子计算中的一个具有挑战性的问题，即如何在不丢失量子信息的情况下耦合分离良好的量子位。应用最新的进展，他们将使用捕获在高Q超导谐振器中的微波光子相干耦合自旋量子比特。一个意外的好处是发现了激光作用。在一个平行的努力，实验，以实现很长的自旋相干寿命同位素纯硅提出。

****Nontechnical abstract****The interdisciplinary research in the MRSEC at Princeton is focused on three directions in materials research. The first exploits recent advances in physics and chemistry to uncover novel "topological" quantum properties of electrons in semiconductors. The research is promising for enabling future electronics with ultralow heat dissipation, and enabling novel approaches to quantum computing. In the second direction, the researchers combine two new technologies that enable the growth of very thin polymer films with specialized physical properties critical for applications in many industries. The third direction seeks to control and manipulate the spin of a single electron trapped in an ultrathin nanowire. Advances will lead to logic elements for quantum computing as well as a new class of broadly tunable lasers. The researchers participate in a broad array of education projects. Each summer, 20 undergraduates, selected from over 400 applicants nationwide, engage in supervised research in preparation for graduate school in science and engineering. In addition, the researchers host 18 high-school and 30 middle-school students from Central High, Trenton, for a rigorous 3-week science-camp (PUMA). The PUMA alumni have achieved a high-school graduation rate of 100%, with most going on to college. In addition, the researchers hold 8 one-day Science fairs each year (some co-organized with the town library) which attract from 300 to 800 K-12 students and their parents to campus. ****Technical abstract****In the first of 3 projects, researchers seek to expand the search for novel topological quantum properties of electrons in insulators, semiconductors and semimetals. Currently, the long-established Bloch theory of crystalline solids is undergoing revision because of topological principles neglected in Bloch theory. Semiconductors in which the energy gap is "inverted" (relative to the atomic limit) exhibit surface states occupied by massless Dirac fermions. Using scanning tunneling microscopy, transport and photoemission experiments, researchers will test key predictions of the new perspective, and search for new topological phases and excitations (e.g. Majorana fermions). In the second project, researchers will apply a laser-ablation technique called MAPLE to grow and investigate ultrathin polymer films deposited under novel conditions that dramatically raise the glass-transition temperature. Combining expertise in fluorescence, nanoscale imaging and simulation, they will address the technologically important issue of why the thermodynamic properties (e.g. the glass transition) of confined polymers differ dramatically from those in bulk polymers. Researchers in the third project will address a challenging problem in the quest for quantum computing, namely how to couple well-separated qubits without losing quantum information. Applying recent advances, they will coherently couple spin qubits using microwave photons trapped in a high-Q superconducting resonator. A serendipitous benefit is the discovery of lasing action. In a parallel effort, experiments to achieve very long spin coherence lifetimes in isotopically pure silicon are proposed.