MACROSCOPIC PHASE COHERENCE FROM SYNTHETIC INTERLAYER COUPLING IN VAN DER WAALS FLAT BANDS

范德瓦尔斯平带中合成层间耦合的宏观相位相干性

• 批准号: 2226850
• 负责人: Andrea Young
• 金额: $ 44.5万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2226850&HistoricalAwards=false
• 关键词: MACROSCOPIC; PHASE; COHERENCE; SYNTHETIC; INTERLAYER

Non-technical description: Many spectacular physical phenomena—and useful device—rely on macroscopic quantum coherence. The most well known example are superconductors, where macroscopic coherence is directly tied both the absence of electrical resistance as well as the emergence of coherent degrees of freedom that form the basis for the best developed platforms for manipulating quantum information. However, macroscopic quantum coherence, in principle, a much broader phenomenon. This project aims to realize new modalities of macroscopic quantum coherence in a broad class of materials known as van der Waals heterostructures. Van der Waals heterostructures consist of successively laminated two dimensional atomic crystals such as graphene; their high crystalline perfection and broad range of tunability put a variety of new quantum coherent states in experimental range. By realizing new states characterized by macroscopic quantum coherence, this project furthers understanding of these phenomena and opens new avenues towards quantum information processing. Synergistic with the research effort is an educational initiative focused on technical workforce development, implemented through a summer school for graduate student across physics, chemistry and materials science working on quantum science related problems. Technical description:The ultimate goal of this project is to create a novel quantum bit based on interlayer coherence in a bilayer exciton condensate. This bit exploits the spontaneous phase coherence predicted to occur in these systems. Bilayer exciton condensates, first discovered in semiconductor quantum wells, have recently been shown to exist in graphene and chalcogenide heterostructures at higher temperatures and under less demanding experimental conditions—particularly in the absence of magnetic fields. The research team is using frequency-dependent interlayer tunneling spectroscopy to directly detect the emergence of macroscopic phase coherence through the excitonic analog of the AC Josephson effect. This new detection modality then allows a broad search for macroscopic coherence in a variety of double layer structures based on band-structure engineered two dimensional double layers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：许多壮观的物理现象（和有用的装置）依靠宏观量子相干性。最著名的例子是超导体，其中宏观的连贯性直接与缺乏电阻以及相干自由度的出现既是构成了操纵量子信息的最佳开发平台的基础。然而，原则上的宏观量子相干性是一种更广泛的现象。该项目旨在实现宏观量子相干性的新方式，以称为范德华异质结构的广泛材料。范德华异质结构由成功层压的二维原子晶体（如石墨烯）组成。它们的高晶体完美和广泛的可可五范围可将各种新的量子相干状态置于实验范围内。通过实现以宏观量子相干性为特征的新状态，该项目进一步了解了这些现象，并为量子信息处理开辟了新的途径。与研究工作的协同作用是一项针对技术劳动力发展的教育计划，该计划是通过暑期学校实施的，旨在针对跨量子科学问题的物理，化学和材料科学跨越物理学，化学和材料科学。技术描述：该项目的最终目标是基于双层激子冷凝物中的层间相干性创建一个新颖的量子位。该位探讨了这些系统中预计会发生的赞助相相一致性。最近在半导体量子井中发现的双层激子冷凝物在高温和较少苛刻的实验条件下（尤其是在没有磁场的情况下），在较高的温度和较少苛刻的实验条件下，在石墨烯和葡萄干化的异质结构中都存在。研究团队正在使用频率依赖性的层间隧道光谱法直接通过AC Josephson效应的激动人心的类似物直接检测宏观相一致性的出现。然后，这种新的检测方式可以基于带构造工程的二维双层层的多种双层结构进行广泛的搜索。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的。