Spatial and temperature dependence of the spectroscopic profile of a magnetic atom adsorbed on a metal surface—Co/Cu(111)
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- Yuki Shimada
- Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
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- Hideaki Kasai
- Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
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- Hiroshi Nakanishi
- Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
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- Wilson Agerico Diño
- Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
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- Ayao Okiji
- Wakayama National College of Technology, Gobō, Wakayama 644-0023, Japan
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- Yukio Hasegawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
説明
<jats:p>As a representative Kondo system, consisting of a magnetic atom adsorbed on a metal surface, we consider a Co adatom on a Cu(111) surface. We introduce general expressions for the tunneling current and the differential conductance dI/dV, and discuss the corresponding spatial and temperature dependencies of the dI/dV line shapes that can be observed when the system is probed with a scanning tunneling microscope (STM). Starting with the STM tip sufficiently far from the Co adatom, the corresponding dI/dV line shape initially has an asymmetric structure about the Fermi level, which gradually becomes symmetric with decreasing STM tip–Co adatom distance, due to the competition between first-order (direct electron tunneling from the STM tip to the metal surface) and second-order (via the magnetic adsorbate) tunneling processes. The corresponding line shape also shows a strong temperature dependence, increasing in width with increasing temperature. As an aid to studying and observing these temperature dependencies experimentally, we suggest the utility of considering the temperature dependence of the derivative of dI/dV with respect to the bias voltage V, i.e., the d2I/dV2 line shape.</jats:p>
収録刊行物
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- Journal of Applied Physics
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Journal of Applied Physics 94 (1), 334-341, 2003-07-01
AIP Publishing