SPIN ELECTRONICS: Carbon Nanotube Based Spin Electronic Devices

该提案是响应21世纪世纪自旋电子学倡议计划征集NSF 02-036而收到的。 该提案的重点是两个原型碳纳米管自旋电子器件的制造和表征：纳米管自旋晶体管和纳米螺旋磁场传感器。对于分子尺度的自旋电子应用，碳纳米管具有令人信服的优势。碳纳米管是具有低密度自旋散射中心的准一维晶体线。因此，电流流过纳米管，电子或自旋散射事件非常少。这使得碳纳米管可用于分子尺度的自旋传输线，自旋检测信号在长传输距离上保持高。自旋信号可以通过门控纳米管来放大或抑制，以改变电子密度。高冲击电流也会在碳纳米管电路中产生非常大的磁矩。这对于磁存储器和开关应用是有用的，以放大和感测局部磁场。纳米管自旋晶体管是具有场效应栅极的铁磁接触纳米管。栅极偏置修改上自旋通道和下自旋通道的传输，并且用于放大或抑制自旋检测信号。纳米螺旋磁传感器是生长成螺旋形状的电接触碳纳米管。由于缺乏电子散射，流经螺旋的电流产生巨大的轨道自旋矩，与外加磁场强烈相互作用。这显著地改变了两个场方向之间的电阻，即使对于低施加场。总之，这些器件显示了一系列的行为，将是有用的先进的自旋电子应用在分子尺度上。为了完成这项工作，PI将联合收割机结合他们在碳纳米管自旋传输，纳米管器件制造，纳米管电特性和纳米管器件建模方面的集体经验。他们将与杜克大学和加州大学滨江分校化学系的合作者密切合作，优化纳米管生长、纳米管分布以进行电学表征，以及纳米管的化学表面改性以用于自旋电子器件应用。作为他们项目的一部分，他们将在自旋电子学和纳米技术这一令人兴奋的领域培训两名研究生。本科生和研究生课程，包括纳米制造，器件建模和电气/光学表征将纳入他们的自旋电子研究进展。

This proposal was received in response to the Spin Electronics for the 21st century Initiative Program Solicitation NSF 02-036. The proposal focuses on fabrication and characterization of two prototype carbon nanotube spin electronic devices: the nanotube spin transistor and the nano-helix magnetic field sensor. For molecular scale spin electronic applications, the carbon nanotube has compelling advantages. Carbon nanotubes are quasi-one-dimensional, crystalline wires having a low density of spin scattering centers. Therefore, current flows through nanotubes with very few electron or spin scattering events. This makes carbon nanotubes useful for molecular scale spin transmission lines, with spin detection signals remaining high over long transmission distances. Spin signals can be amplified or suppressed by gating the nanotube to change the electron density. High ballistic current flow also produces anomalously large magnetic moments in carbon nanotube circuits. This is useful for magnetic memory and switching applications to amplify and sense local magnetic fields.The nanotube spin transistor is a ferromagnetically contacted nanotube with a field effect gate. The gate bias modifies the transmission of the up and down spin channels, and acts to amplify or suppress the spin detection signal. The nano-helix magnetic sensor is an electrically contacted carbon nanotube grown into a helical shape. Due to the lack of electron scattering, current flow through the helix produces a giant orbital spin moment, which interacts strongly with applied magnetic field. This dramatically alters the resistance between the two field directions, even for low applied fields. Together, these devices display a range of behavior that will be useful for advanced spin electronic applications on the molecular scale. To accomplish this work, the PIs will combine their collective experience in carbon nanotube spin transport, nanotube device fabrication, nanotube electrical characterization and nanotube device modeling. They will work closely with collaborators within the chemistry departments at Duke University and UC Riverside to optimize nanotube growth, distribution of nanotubes for electrical characterization, and chemical surface modification of nanotubes for spin electronic device applications. As part of their project, they will be training two graduate students in the exciting area of spin electronics and nanoscale technology. The undergraduate and graduate curriculum including Nanoscale fabrication, Device Modeling, and Electrical/ Optical Characterization will incorporate their spin electronic research advances.