Majorana Fermions

马约拉纳费米子

• 批准号: 2105454
• 金额: --
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2105454
• 关键词: Majorana; Fermions

There is currently great excitement surrounding the investigation of Majorana zero modes (MZMs) in topological superconducting networks: A possible technology route to an all solid state quantum processor. Recently, significant work on semiconductor nanowires has offered tentative evidence for the existence of MZMs, which are predicted by theory to be robust quantum states that can be exploited for quantum processing, and yet unlike other demonstrator quantum technologies are potentially realisable in familiar solid state technology. However there is now considerable debate in the literature about the certainty of these observations, and the necessary extension to more exploitable planar (2DEG) technology is elusive. States occur at the interface between a one-dimensional (1D) semiconductor that has strong spin-orbit coupling (SOC), and a proximity superconductor. Through electrical study this project will explore state-of-the-art Indium Antimonide (InSb) based quantum well heterostructures that have the largest SOC of all the compound semiconductors, and investigate MZM formation at the interface with superconducting material.We will exploit material grown at our long standing collaborators at the University of Sheffield (EPSRC UK National epitaxy facility), together with Warwick University, and a new collaboration with the group of Chris Palmstrom at the University of California Santa Barbara (UCSB). Material will be both grown with superconducting Al on the surface, or have superconducting material deposited whilst investigating different sulfonation surface preparations to achieve different band alignments of the superconductor to semiconductor interface.The project will involve device fabrication within the Institute for Compound Semiconductors (ICS) cleanroom facility, using both photo and electron beam lithography, working alongside process engineers to build on existing process technology to investigate proximity induced superconduction in the semiconductor material, low leakage surface gating to enable the creation of tunnel barriers, and ultimately the unambiguous observation of Majorana Fermions. These devices will be measured at low temperature (potentially down to 15mK) with high sensitivity electrical conductivity measurement, and where appropriate high magnetic field.

目前，拓扑超导网络中马约拉纳零模式（MZMs）的研究非常令人兴奋，这是实现全固态量子处理器的可能技术途径。最近，在半导体纳米线方面的重要工作为MZMs的存在提供了初步证据，理论上预测MZMs是可以用于量子处理的鲁棒量子态，但与其他演示量子技术不同的是，它有可能在熟悉的固态技术中实现。然而，目前文献中关于这些观察结果的确定性存在相当大的争论，并且必要的扩展到更可开发的平面（2DEG）技术是难以捉摸的。态发生在具有强自旋轨道耦合（SOC）的一维半导体和邻近超导体之间的界面上。通过电学研究，该项目将探索最先进的基于锑化铟（InSb）的量子阱异质结构，它具有所有化合物半导体中最大的SOC，并研究超导材料界面上MZM的形成。我们将利用谢菲尔德大学（EPSRC英国国家外延设施）与华威大学长期合作的材料，以及与加州大学圣巴巴拉分校（UCSB）的克里斯·帕姆斯特罗姆（Chris Palmstrom）小组的新合作。材料将在表面生长超导Al，或者在研究不同磺化表面制备的同时沉积超导材料，以实现超导体与半导体界面的不同能带排列。该项目将涉及化合物半导体研究所（ICS）洁净室设施内的设备制造，使用光刻和电子束光刻，与工艺工程师一起在现有工艺技术的基础上研究半导体材料中的邻近感应超导，低泄漏表面门控以实现隧道屏障的创建，并最终明确观察马约拉纳费米子。这些设备将在低温（可能低至15mK）下进行高灵敏度电导率测量，并在适当的高磁场下进行测量。