Observations of quantum entangled states and quantum critical behavior by using a precise probing method of microwave near-field

利用微波近场精密探测方法观测量子纠缠态和量子临界行为

• 批准号: 21200035
• 负责人: KITANO Haruhisa
• 金额: $ 19.8万
• 依托单位: Aoyama Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Innovative Areas (Research a proposed research project)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21200035/
• 关键词: 超伝導体; 量子もつれ合い; マイクロ波; 空洞共振器; 量子相転移; 超伝導材料・素子; マイクロ波近接場; ジョセフソン接合; ジョセブソン接合; 超伝導体; 量子もつれ合い; マイクロ波; 空洞共振器; 量子相転移; 超伝導材料・素子; マイクロ波近接場; ジョセフソン接合; ジョセブソン接合

Quantum entangled states become essentially important in both regions of condensed matter physics and quantum information technology. Toward a complete understanding of such states, we study the development of a microwave microscope to probe the quantum critical behavior in the neighborhood of quantum critical point, and the design of a superconducting cavity resonator to investigate the quantum entangled states generated by using a quantum electrodynamics theory. We found that a spatial resolution of the microwave microscope is strongly enhanced by utilizing a microwave near-field, which is realized by the insertion of a metallic needle into a cavity resonator. We also found that such an insertion of the metallic needle is useful for a precise control of the coupling constant between the Josephson quantum bits and the microwave photons at low temperatures, which is required to create the quantum entangled states.

量子纠缠状态在凝结物理物理和量子信息技术的两个区域中都非常重要。为了完全理解这种状态，我们研究了微波显微镜的发展，以探测量子关键点附近的量子临界行为，以及设计超导腔谐振器的设计，以研究使用量子电动力学理论产生的量子纠缠状态。我们发现，微波显微镜的空间分辨率通过使用微波近场可以强烈增强，这是通过将金属针插入空腔谐振器中实现的。我们还发现，将金属针的这种插入可用于精确控制约瑟夫森量子位与低温下的微波光子之间的耦合常数，这是创建量子纠缠状态所必需的。