Prototype of Time-resolved Magnetic Circular Dichroism Spectroscopic Nanoscope Using Scanning Tunneling Microscope

• Project/Area Number: 26390027
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nanomaterials engineering
• Research Institution: Shiga University of Medical Science
• Principal Investigator: Mera Yutaka 滋賀医科大学, 医学部, 教授 (40219960)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: 走査トンネル顕微鏡 / 磁気円二色性 / 探針増強効果 / 磁気円二色性分光 / ナノ顕微分光 / ナノ顕微分光法

Outline of Final Research Achievements

A new experimental system of microscopic nano-spectroscopy was prototyped, combining magnetic circular dichroism spectroscopy and scanning tunneling microscope with atomic resolution. From the consideration of local optical field enhancement in the vicinity of a metal tip, it was found that optical field enhancement is very weak when circular polarization modulation is used, as compared with ordinary light STM. As a sample candidate for dichroic spectroscopy, structural evaluation of amyloid beta at the atomic level was performed. Fibrils and aggregation nuclei of amyloid beta were observed by scanning probe microscopes.