Spectroscopy of Semiconductor Nanostructures in High Magnetic Fields

技术摘要：在过去的几十年里，固体在强磁场中表现出一系列奇特的现象。磁场通过轨道（朗道）量子化和自旋（塞曼）分裂产生电子能谱的剧烈变化。特别是，磁场中的量子约束半导体结构具有完全可调的电子密度、态密度和约束能量，是系统研究非平凡效应的理想选择。提出的研究将解决与纳米结构中的量子相干性和相互作用相关的基本问题，例如：独立的电子-空穴对如何发展宏观相干性？一维激子在量子简并密度下有多稳定？共振电子-声子相互作用将如何改变狄拉克费米子的能级？澄清这些问题不仅将促进我们对固体中载流子相互作用的理解，而且还将为利用相干和多体效应开辟新的器件可能性。此外，在尖端项目中培养本科生和研究生将培养下一代半导体光学专家。最后，通过与PI的国家科学基金会国际研究和教育合作伙伴关系的独特联系，将为纳米日本的校友提供一个独特的机会：本科生暑期纳米技术研究计划，以在国家高磁场实验室进行暑期实习，进一步提高他们的研究经验。摘要：放置在超强磁场中的固体有时会表现出奇怪的现象，包括量子霍尔效应，即在特定的磁场值下电阻消失。磁场通过轨道量子化和自旋分裂极大地改变固体中电子的能量，从而为控制量子现象提供了一种强有力的手段。特别是，纳米结构在磁场中以高度可控的方式研究复杂效应是理想的。晶体生长和纳米制造技术的进步使人们能够获得具有定制特性的最高结晶度样品。该项目将通过磁光实验研究三种原型纳米系统（半导体量子阱、碳纳米管和石墨烯）中的新型磁场诱导现象。这些研究不仅将促进我们对固体中电子行为的理解，而且还将为光电器件开辟新的可能性。此外，本科生和研究生将接受尖端项目的培训，成为下一代半导体光学专家。此外，通过与PI的国家科学基金会国际研究和教育合作伙伴关系基金的独特联系，纳米日本：本科生夏季纳米技术研究计划的校友将被邀请到国家高磁场实验室（NHMFL）进行暑期实习，以进一步发展他们的研究经验。通过研究生和NHMFL研究人员的直接指导，他们将得到大力鼓励，继续在该领域进行研究生学习和研究。

TECHNICAL ABSTRACT: Solids in strong magnetic fields have exhibited an array of exotic phenomena for the past several decades. A magnetic field produces drastic modifications in electronic energy spectra through orbital (Landau) quantization and spin (Zeeman) splitting. In particular, quantum-confined semiconductor structures in magnetic fields are ideal for studying non-trivial effects in a systematic manner with fully tunable electron densities, densities of states, and confinement energies. The proposed research will address fundamental questions related to quantum coherence and interactions in nanostructures such as: How will independent electron-hole pairs develop macroscopic coherence? How stable will one-dimensional excitons be at quantum degenerate densities? and How will resonant electron-phonon interactions modify energy levels of Dirac fermions? Clarifying these questions will not only advance our understanding of carrier interactions in solids, but also open up new device possibilities for utilizing coherent and many-body effects. In addition, training undergraduate and graduate students in cutting-edge projects will produce next generation experts in semiconductor optics. Finally, through the unique linkage with the PI's NSF Partnerships for International Research and Education grant, a unique opportunity will be provided for alumni of the NanoJapan: Summer Nanotechnology Research Program for Undergraduates to further their research experience with a summer internship at the National High Magnetic Field Laboratory.NON-TECHNICAL ABSTRACT: Solids placed in super-strong magnetic fields can sometimes exhibit bizarre phenomena, including the quantum Hall effect where the resistance vanishes at special values of magnetic fields. A magnetic field drastically modifies electrons' energies in solids through orbital quantization and spin splitting, thereby providing a powerful means for controlling quantum phenomena. In particular, nanostructures in magnetic fields are ideal for studying complicated effects in a highly-controllable manner. Advances in crystal growth and nanofabrication technology allow one to obtain samples of highest crystallinity with tailored properties. This project will examine novel magnetic-field-induced phenomena in three prototypical nanosystems -- semiconductor quantum wells, carbon nanotubes, and graphene -- through magneto-optical experiments. These studies will not only advance our understanding of electron behaviors in solids but also open up new possibilities for optoelectronic devices. In addition, undergraduate and graduate students will be trained in cutting-edge projects to become next generation experts in semiconductor optics. Furthermore, through the unique linkage with the PI's NSF Partnerships for International Research and Education grant, alumni of the NanoJapan: Summer Nanotechnology Research Program for Undergraduates will be invited to further their research experience with a summer internship at the National High Magnetic Field Laboratory (NHMFL). They will be given strong encouragement to pursue further graduate study and research in this field through the direct mentorship of graduate students and NHMFL researchers.