Investigating many body effects in quantum structures

本实验博士项目的目的是研究低温下量子输运在低维半导体纳米结构中的多体效应。近年来，当低维半导体纳米结构被静电限制在一维（1D）量子结构中时，人们提出并发现了各种新的量子效应，这些量子结构具有以前未知的独特特征。其中一个特征是通过弱约束准一维量子线观察分数量子化电导。通过一维量子线的电导通常用N（2e2/h）表示，其中N = 1,2,3…为一维能量子带的个数。当一维电子受到强库仑相互作用时，一条一维电子线会重新排列成锯齿状，其电导率明显低于2e2/h。这些最近发现的现象的多体效应将在新的实验装置中进行全面研究，这将产生更好的约束势调谐，以及定制相邻电子之间分离的能力。该项目的一个重要组成部分将是研究之字形相位，它有望拥有许多量子特性，包括电子配对和纠缠。除了制造量子器件的洁净室培训外，学生还将接受在极低温度和高磁场下进行低噪声量子输运测量的广泛培训和监督。此外，伦敦大学学院还将提供额外的培训项目，并有机会与跨学科研究团队和行业建立联系。将有很多机会在国内和国际会议上展示工作成果，并与研究人员和行业合作伙伴建立联系。该项目将对下一代量子计算设备以及凝聚态物理的新基本量子基础产生广泛影响。目前的研究项目属于EPSRC的主题领域，如物理和工程科学以及量子技术。

The objective of this experimental Ph.D. project is to investigate many-body effects in low-dimensional semiconductor nanostructures using quantum transport at cryogenic temperatures. In recent years, a variety of new quantum effects have been proposed as well as discovered when a low-dimensional semiconductor nanostructure is electrostatically confined to create a one-dimensional (1D) quantum structure exhibiting unique characteristics previously unknown. One of the characteristics is the observation of fractional quantised conductance through a weakly confined quasi-1D quantum wire. The conductance through a 1D quantum wire is commonly represented by N(2e2/h), where N = 1,2,3 ... is the number of 1D energy subbands. When 1D electrons are subjected to strong Coulomb interactions, a line of 1D electrons rearranges itself into a zigzag which remarkably is found to exhibit fractional quantised conductance below 2e2/h. The many-body effects of these recently discovered phenomena will be comprehensively studied in new experimental devices which will produce better tuning of the confinement potential, as well as the ability to customise the separation between neighbouring electrons. A significant component of the project will be investigating the zigzag phase, which is expected to possess numerous quantum properties including electron pairings and entanglement. In addition to cleanroom training for fabricating quantum devices, the student will receive extensive training and supervision for performing low-noise quantum transport measurements at extremely low temperatures and high magnetic fields. Furthermore, additional training programmes would be available through UCL, as well as the opportunity to network with interdisciplinary research teams and industries. There will be many opportunities to present work at national and international conferences, and to build contacts with researchers and industry partners. The project will have broad implications for the next generation of quantum computing devices as well as new fundamental quantum foundations of condensed matter physics.The current research project falls into the EPSRC thematic areas such as physical and engineering sciences and quantum technologies.