Materials World Network: Spin Effects in Quasi-1D Systems of Narrow Gap Semiconductors

发展电子和信息技术新范例的可能性激发了全世界对自旋电子学的兴趣，自旋电子学基于操纵固体中电荷载流子的本征自旋，以开发用于高速、低功率器件和电路的新的、有效的功能。目前的研究工作，涉及在布法罗大学（UB）和鲁尔大学，波鸿（RUB）的小组之间的密切合作的目标是：发展的自旋轨道（SO）相互作用的准一维系统中的InAs基异质结的基本物理的充分理解，发现新的自旋相关的现象，并探索开发新的自旋电子器件的机会。强SO耦合效应起源于结构中缺乏反转对称性，这可以通过生长或施加外部电场来控制。InAs的窄的基本能隙和大的自旋轨道分裂也起着很大的作用。两个主要的研究活动是：1）光响应和吸收的电偶极子自旋共振的量子霍尔边缘通道的量子威尔斯阱的研究;和2）电输运，磁输运和电偶极子自旋共振光刻制造的量子线在类似的InAs基异质结构的研究。从两个系统的结果将进行比较和异同将提供更深入的了解这些系统的基本自旋物理。 作为电场和磁场的函数的太赫兹和低频实验将提供关于这些结构中的场的相互作用和SO相互作用的基本信息。从这一协调努力中获得的详细理解应该允许定制复杂的一维结构，例如，在马赫-曾德尔干涉仪中将短量子线与量子霍尔边缘通道相结合，用于自旋相关的相干测量。MWN的资金将支持美国和德国团体之间的密切耦合的实验研究和教育计划。合作的理论和材料生长（分子束外延）的努力也支持这项工作。这两个小组在这些结构的物理学和互补的专业知识方面有共同的兴趣。通过该计划的基础知识的进步将影响自旋电子学和量子信息处理领域。直接参与这些研究的研究生将通过学生和PI的定期交流接受基础物理，材料科学和纳米纤维的独特广泛的多学科教育以及文化教育。本科生将通过在UB的培训和独立学习获得国外的研究经验，并在初夏访问我们在RUB的合作伙伴实验室。

The possibility of developing new paradigms for electronics and information technology has motivated world-wide interest in spintronics, which is based on manipulating the intrinsic spin of charge carriers in solids to develop new, efficient functionalities for high-speed, low-power devices and circuits. The goals of the present research effort, involving close collaboration between groups at the University at Buffalo (UB) and the Ruhr Universitaet, Bochum (RUB), are: to develop a full understanding of the basic physics of the spin-orbit (SO) interaction in quasi-one-dimensional systems in InAs-based heterostructures; to discover new spin-related phenomena; and to explore opportunities for developing novel spintronic devices. Strong SO coupling effects originate in the lack of inversion symmetry in the structures, which can be controlled by growth or by application of an external electric field. The narrow fundamental gap and large spin-orbit splitting of InAs also play a strong role. The two main research activities are: 1) photoresponse and absorption studies of electric-dipole spin resonance in Quantum Hall edge channels in InAs quantum wells; and 2) electrical transport, magnetotransport and electric-dipole spin resonance studies of lithographically fabricated quantum wires in similar InAs-based heterostructures. Results from the two systems will be compared and similarities and differences will provide deeper insight into the fundamental spin physics of these systems. Terahertz and low frequency experiments as a function of electric and magnetic fields will provide essential information on the interplay of the fields and the SO interaction in these structures. The detailed understanding derived from this coordinated effort should allow tailoring complex one-dimensional structures, for example, combining short quantum wires with quantum Hall edge channels in a Mach-Zehnder interferometer for spin-dependent coherence measurements. The MWN funding will support a closely coupled experimental research and education program, between the US and German groups. Collaborative theoretical and materials growth (molecular beam epitaxy) efforts also support this work. The two groups have common interests in the physics of these structures and complementary expertise. The advancement of fundamental knowledge through this program will impact the fields of spintronics and quantum information processing. Graduate students directly involved in these studies will receive a unique broad, multidisciplinary education in basic physics, materials science, and nanofabrication, as well as cultural education through the regular exchanges of students and the PIs. Undergraduate students will be provided with a research experience abroad via training and independent study at UB, and a one month early summer visit to our partner's laboratory at RUB.