Scanning probe microscopy analysis of the changes in force and electric current with the collapse of tunneling barrier between two bodies at closer separation

2014 Fiscal Year Final Research Report

• Project/Area Number: 24340068
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Kanazawa University
• Principal Investigator: ARAI Toyoko 金沢大学, 数物科学系, 教授 (20250235)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 表面・界面 / 走査型プローブ顕微鏡 / トンネル障壁 / 相互作用力

Outline of Final Research Achievements

In this study, we measured the force and electric current as well as their dependences on the applied bias voltage and the separation between two bodies, which were brought closer and in contact using a lab-made system of noncontact atomic force microscopy combined with scanning tunneling microscopy. From the obtained results, we discussed the effects of collapse of tunneling barrier during the process of bond formation between them. For the covalent bond between Si atoms, we analyzed the relationship between the strength of the covalent bond and the tunneling current by applying the bias voltage between a tip and a Si sample, while the surface states on both sides were energetically tuned under the bias voltage, leading to a quantum mechanical resonating state. For an H-terminated Si adatom and a Si atom on the tip, we measured the strength of hydrogen bond between them, and evaluated the binding energy of the hydrogen bond.

Free Research Field

表面科学、ナノ物理学