Vortex Pinning in Thin Film Superconductors by Controlled Pinning Structures

w：\awards\awards96\*. doc 9801921 Schuller 本实验研究计画系利用控制性钉扎结构来探讨薄膜超导体中的涡旋钉扎现象。这是一个联合的实验/理论研究的涡流在低和高Tc的薄膜受到人工钉扎的物理。 钉扎结构是使用最先进的光刻工艺设计的。研究中的钉扎结构包括由正常或磁性材料制成的规则和弱无序的"孔"和/或"条"阵列。 这些阵列的钉扎特性在很宽的范围内的温度，场和材料参数将其特征在于运输，噪声，和直接成像测量。 新颖的钉扎模式将被用来扩大钉扎阶段的磁场范围很广，超出了标称匹配场，以提高涡流钉扎。它们还提供了新的"媒介"，在其中可以研究各种新的和有趣的涡旋现象。 理论是这个项目固有的一部分。 新的制造方法和设备将使用最先进的薄膜技术与前沿光刻工艺一起开发。该研究计划是跨学科的性质，并涉及几个前和研究生的研究人员在其活动。他们将熟悉适用于凝聚态物理，微电子，磁记录和传感器以及超导器件的研究设备和方法。 他们的培训将为工业，政府实验室或学术界的职业生涯做好准备。 %这个实验基础研究项目是关于提高超导薄膜的载流能力。超导体在磁场存在下的"临界"电流受到"钉扎中心"的影响，钉扎中心充当穿透薄膜的磁通线（涡旋）的锚。 临界电流可以增加 通过增加钉扎。本研究利用控制性钉扎结构探讨薄膜超导体中的涡旋钉扎。这是一个联合的实验/理论研究的涡流在低和高Tc的薄膜受到人工钉扎的物理。钉扎 结构 是 工程化 使用 最先进的光刻工艺。研究中的钉扎结构包括由正常或磁性材料制成的规则和弱无序的"孔"和/或"条"阵列。这些阵列的钉扎特性在很宽的范围内的温度，场和材料参数将其特征在于运输，噪声，和直接成像测量。新颖的钉扎模式将被用来扩大钉扎阶段的磁场范围很广，超出了标称匹配场，以提高涡流钉扎。它们还提供了新的"媒介"，在其中可以研究各种新的和有趣的涡旋现象。 理论是项目的固有部分。新的制造方法和设备将使用最先进的薄膜技术与前沿光刻工艺一起开发。 该研究计划是跨学科的性质，并涉及几个前和研究生的研究人员在其活动。他们将熟悉适用于凝聚态物理，微电子，磁记录和传感器以及超导器件的研究设备和方法。他们的训练会很出色 为工业界的职业生涯做准备， 政府实验室或学术界。 ***

w:\awards\awards96\*.doc 9801921 Schuller This experimental research project is concerned with vortex pinning in thin film superconductors by controlled pinning structures. It is a joint experimental/theoretical study of the physics of vortices in low and high Tc thin films subject to artificial pinning. The pinning structure is engineered using state-or-the-art lithography processes. Pinning structures under study include regular and weakly disordered arrays of "holes", and/or "stripes" made of normal or magnetic materials. The pinning characteristics of these arrays over a wide range of temperature, field and materials parameters will be characterized by transport, noise, and direct imaging measurements. Novel pinning patterns will be used to expand the pinned phase to a broad range of magnetic fields, beyond the nominal matching field, to enhance vortex pinning. They also provide new "media" in which a variety of new and interesting vortex phenomena can be studied. Theory is an inherent part of the project. New fabrication methods and devices will be developed using state of the art thin film techniques together with forefront lithography processes. This research program is interdisciplinary in nature and involves several pre- and post-graduate researchers in its activities. They will become familiar with research equipment and methods applicable to condensed matter physics, microelectronics, magnetic recording and sensors, and superconducitng devices. Their training will be excellent preparation for careers in industry, government laboratories or academia. %%% This experimental basic research project is concerned with increasing the current carrying capacity of superconducting thin films. The "critical" current of a superconductor in the presence of a magnetic field is influenced by "pinning centers" which act as anchors fo r the magnetic flux lines (vortices) which penetrate the thin film. The critical current can be increased by increasing the pinning. This study investigates vortex pinning in thin film superconductors by controlled pinning structures. It is a joint experimental/theoretical study of the physics of vortices in low and high Tc thin films subject to artificial pinning. The pinning structure is engineered using state-or-the-art lithography processes. Pinning structures under study include regular and weakly disordered arrays of "holes", and/or "stripes" made of normal or magnetic materials. The pinning characteristics of these arrays over a wide range of temperature, field and materials parameters will be characterized by transport, noise, and direct imaging measurements. Novel pinning patterns will be used to expand the pinned phase to a broad range of magnetic fields, beyond the nominal matching field, to enhance vortex pinning. They also provide new "media" in which a variety of new and interesting vortex phenomena can be studied. Theory is an inherent part of the project. New fabrication methods and devices will be developed using state of the art thin film techniques together with forefront lithography processes. This research program is interdisciplinary in nature and involves several pre- and post-graduate researchers in its activities. They will become familiar with research equipment and methods applicable to condensed matter physics, microelectronics, magnetic recording and sensors, and superconducitng devices. Their training will be excellent preparation for careers in industry, government laboratories or academia. ***