Surface/Interface Phenomena and Topological Order in Emerging Quantum Materials

非技术摘要：近年来，人们对一类称为拓扑绝缘体（TI）的新兴新材料的兴趣正在增加，这些材料在其表面/界面处显示出意想不到的量子特性。这导致了量子科学的巨大进步，并具有未来量子设备的潜力，这些设备可以在信息存储和传输方面实现节能。这些新材料可以携带电流而不会耗散，并能够提高现有技术的性能，如自旋电子学（用于计算机数据存储，通信和传感）。另一种拓扑相关现象是一种称为马约拉纳束缚态（MBS）的新型量子态，它可以通过将具有不同物理现象（拓扑，超导性，磁性）的材料结合在一起而出现在TI中，这可能导致未来的高度容错量子计算。在这个项目中，学生以及年轻的科学家获得知识，并在许多先进领域的培训，以及推动物理和材料科学的前沿。有可能为建立节能量子电子学奠定基础，以彻底改变未来的信息技术。技术摘要：二维量子相干特性的演示和界面铁磁性的意外稳定，以更高的温度在TI通过接近耦合到铁磁绝缘体，促使调查：i）在较高温度下在铁磁TI中实现量子相干性质的出现，ii）自旋极化手征电流在与磁绝缘体杂化时在具有邻近感生带隙的TI中的量子行为，以及iii）探测非常规超导配对，用隧道谱研究了磁性TI边缘导电沟道中的电子自旋极化和量子相干性。这些目标是可以实现的基础上，我们广泛的先前相关的多学科知识与薄膜异质结构的性能，使用最先进的分子束外延系统的薄膜生长和测量设施，包括原子水平的接口表征利用国家设施。 在该计划下，计划对学生（包括高中生暑期课程）和年轻科学家进行量子相干拓扑驱动现象领域的教育和培训。

Non-Technical Abstract:In recent years interest is increasing in a class of emerging new materials called topological insulators (TI) displaying unexpected quantum properties at their surfaces/interfaces. This has led to vast advancement in quantum science, and with potential for future quantum devices that can be energy efficient for information storage and transmission. These new materials can carry current without dissipation and are capable of enhancing the performance in existing technology such as spintronics (used in computer data storage, communication and sensing). Another topology related phenomenon is a new type of quantum state called Majorana bound states (MBS) that can appear in TIs by combining materials with different physical phenomena (topology, superconductivity, magnetism), which may lead to future highly fault-tolerant quantum computing. In this project, students as well as young scientists acquire knowledge and train in many advanced areas, as well as push the frontiers of physics and material science. There is potential to lay the foundation for establishing energy efficient quantum electronics to revolutionize the future information technology. Instruments, patents and knowledge developed during this research would be made available to companies.Technical Abstract:The demonstration of two-dimensional quantum coherent properties and unexpected stabilization of interfacial ferromagnetism to much higher temperatures in TI by proximity coupling to a ferromagnetic insulator, has prompted the investigation: i) to reach the occurrence of quantum coherent properties in a ferromagnetic TI at a higher temperatures, ii) the quantum behavior of spin polarized chiral current in TIs with proximity induced gap when hybridized with a magnetic insulator, and iii) probe unconventional superconducting pairing, the electron spin polarization and quantum coherence in the edge conduction channel of magnetic TI by tunneling spectroscopy. These goals are achievable based on our extensive previous related multidisciplinary knowledge with thin film heterostructure properties using state of the art molecular beam epitaxial system for film growth and measurement facilities, including atomic level characterization of interfaces utilizing the national facilities. Education and training of students (including high school students summer programs) and young scientists in the areas dictated quantum coherent topology driven phenomena are planned under this program.