SPIN ELECTRONICS: Spintronics with Novel Half-Metals: Computational Design

自旋电子学：新型半金属自旋电子学：计算设计

• 批准号: 0225007
• 负责人: Ching Yao Fong
• 金额: $ 24万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-01 至 2006-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0225007&HistoricalAwards=false
• 关键词: SPIN; ELECTRONICS; Spintronics; Novel; Half

0225007FongThis proposal was received in response to the Spin Electronics for the 21st century Initiative, Program Solicitation NSF 02-036. The proposal focuses on the computational design of novel quantum structures in the forms of heterojunctions, quantum wells, and quantum dots composed of half-metallic compounds in zinc-blende structure with both magnetically and nonmagnetically doped semiconductors as new materials for spintronics. The unique features possessed by these half-metals compounds are: (A) the half metallic properties of each compound are preserved for a range of each lattice constant, (B) large magnetic moments (= 1 uB), (C) high Curie temperature (= 400oK), and (D) less intrinsic scattering (greater coherence) than for dilute magnetically doped semiconductors due to the fact that the half metals are stoichiometric compounds. They inspire a singular opportunity for making novel quantum structures. The outcome of this proposal will include (1) the technological information of quantum structures for spintronic applications, (2) specific scientific knowledge about the effects of interfaces, surfaces on the magnetic and electronic properties of the proposed quantum structures, and (3) the selections of elements serving as antisurfactants to grow half-metallic quantum dots. Specifically relevant to (1), The PIs will provide: (a) the compositions of quantum structures involving chromium and manganese compounds with magnetic and nonmagnetic doped semiconductors and exhibiting half-metallic behaviors as new spintronic materials, (b) the magnetic and electronic properties of the promising quantum structures, (c) the possibility of making spin polarized Schottky barriers, and (d) the conditions for ballistic spin transport in heterojunctions, and quantum wells. For (2), the information will lead them to understand: (i) Whether spin polarized Schottky barriers are being formed in heterojunctions and quantum wells made of half metal compounds with various doped semiconductors, and do the interfaces affect the corresponding half-metallic character and magnetic moment? (ii) What are the effects of the Schottky barrier formed by the metallic spin channel of a heterojunction on its semiconducting spin channel? (iii) Do subbands formed in a quantum well exhibit the stepwise feature in the conductance? (iv) How do the magnetic properties of a quantum dot made of a half-metal compound depend on the sizes of the dots, and on cation- versus anion-terminated surface? Finally, the results relevant to (3) will provide guidelines for facilitating the growth of quantum dots composed of half-metals with the zinc-blende structure.

0225007Fong此提案是为了响应 21 世纪自旋电子学计划、NSF 02-036 计划征集而收到的。该提案重点关注由闪锌矿结构中的半金属化合物组成的异质结、量子阱和量子点形式的新型量子结构的计算设计，以及磁性和非磁性掺杂半导体作为自旋电子学的新材料。这些半金属化合物拥有的独特特征是：(A) 在每个晶格常数范围内保留每种化合物的半金属特性，(B) 大磁矩 (= 1 uB)，(C) 高居里温度(= 400oK)，以及 (D) 由于半金属是化学计量化合物，因此比稀磁掺杂半导体具有更少的固有散射（更高的相干性）。它们激发了制造新颖量子结构的独特机会。 该提案的成果将包括（1）用于自旋电子应用的量子结构的技术信息，（2）关于界面、表面对所提出的量子结构的磁和电子特性的影响的具体科学知识，以及（3）选择用作抗表面活性剂的元素来生长半金属量子点。特别与（1）相关，PI将提供：（a）涉及铬和锰化合物的量子结构的组成，具有磁性和非磁性掺杂半导体并表现出作为新自旋电子材料的半金属行为，（b）磁性和电子特性有前途的量子结构，（c）制造自旋极化肖特基势垒的可能性，以及（d）异质结和量子阱中弹道自旋输运的条件。对于（2），这些信息将引导他们了解：（i）在由各种掺杂半导体的半金属化合物制成的异质结和量子阱中是否形成自旋极化肖特基势垒，以及界面是否影响相应的半金属特性和磁矩？ (ii) 异质结的金属自旋通道形成的肖特基势垒对其半导体自旋通道有何影响？ (iii) 量子阱中形成的子带是否表现出电导的阶梯特征？ (iv) 由半金属化合物制成的量子点的磁性如何取决于点的尺寸以及阳离子与阴离子封端的表面？最后，与（3）相关的结果将为促进由闪锌矿结构的半金属组成的量子点的生长提供指导。