SGER: A Self Assembled Spintronic Quantum Gate

SGER：自组装自旋电子量子门

• 批准号: 0089893
• 负责人: Supriyo Bandyopadhyay
• 金额: $ 4.5万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-10-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0089893&HistoricalAwards=false
• 关键词: SGER; Self; Assembled; Spintronic; Quantum

A small grant is requested for exploratory research leading to the possible demonstration of a critical element for a nanoscale universal quantum gate.A novel gate structure will be electrochemically self assembled by sequential electrodeposition of ferromagnetic and semiconducting layers inside the pores of a self-assembled porous film with ~ 10-nm sized pores. A qubit will be encoded by the spin polarization of a single electron injected into the depleted semiconductor layer from the ferromagnetic contact and trapped there by Coulomb blockade. Single qubit rotations will be effectedby modulating the spin splitting energy in the semiconductor layer with an external electrostatic gate potential, utilizing the Rashba effect. The uniqueness of this approach is that it utilizes a self-assembled structure (thereby obviating the need for complicated lithography; some lithography is needed for input/output connections and gate contacts) and it relies on electrical control of the qubit as opposed to magnetic field control envisaged in other comparable schemes. Since electrical switching is faster and moreconvenient on a chip, this paradigm has distinct advantages.The risk involved in the project is the uncertainty of coherent spin injectionacross a ferromagnetic/semiconductor interface. The risk is however mitigated by the fact that spin injection is easier across small area interfaces and there exists experimental evidence of spin injection across the interface of carbon nanotubes and ferromagnetic metals which is ofa quality comparable to or worse than what we expect in our fabrication scheme. If successful, this project will lead to the only self-assembled, all-electric spintronic quantum gate.A self assembled spintronic quantum gate will ultimately allow the creation of a self-assembled quantum circuit with quantum connectors linking different gates,as well as quantum memory elements. Since the self assembled structures are extremely dense, it is expect a qubit density ofmore than 10E11/cmE2 that translates to a storage density equivalent tothat of 2**{10E9} classical bits in a 1-cmE2 area which exceeds the storage capacity of all the hard disks that could be made with all the material in the universe over the life of the universe.

需要一笔小额赠款用于探索性研究，从而可能演示纳米级通用量子门的关键元素。通过在自组装多孔的孔内顺序电沉积铁磁层和半导体层，将通过电化学方式自组装一种新颖的门结构薄膜具有〜10纳米大小的孔。量子位将通过从铁磁接触注入耗尽半导体层并被库仑封锁捕获的单个电子的自旋极化来编码。利用拉什巴效应，通过使用外部静电门电势调制半导体层中的自旋分裂能量来实现单量子位旋转。这种方法的独特之处在于它采用自组装结构（从而无需复杂的光刻；输入/输出连接和栅极接触需要一些光刻），并且它依赖于量子位的电气控制而不是磁场其他类似方案中设想的控制。由于电切换在芯片上更快、更方便，因此这种范例具有明显的优势。该项目涉及的风险是铁磁/半导体界面上相干自旋注入的不确定性。然而，由于自旋注入在小面积界面上更容易，并且存在跨碳纳米管和铁磁金属界面的自旋注入的实验证据，其质量与我们在制造方案中预期的质量相当或更差，因此降低了风险。如果成功，该项目将产生唯一的自组装全电自旋电子量子门。自组装自旋电子量子门最终将允许创建自组装量子电路，其中具有连接不同门的量子连接器以及量子记忆元素。由于自组装结构非常致密，预计量子位密度将超过 10E11/cmE2，这意味着存储密度相当于 1-cmE2 区域中 2**{10E9} 经典位的存储密度，这超过了所有量子位的存储容量。在宇宙生命周期内可以用宇宙中所有材料制造的硬盘。