Reconstruction of the local density of states in Ag(111) surfaces using scanning tunneling potentiometry
Reconstruction of the local density of states in Ag(111) surfaces using scanning tunneling potentiometry
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使用扫描隧道电位法重建 Ag(111) 表面的局域态密度
DOI：
10.1103/physrevb.76.193407
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发表时间：
2007
影响因子：
3.7
通讯作者：
R. Ulbrich
中科院分区：
文献类型：
--
作者：
J. Homoth;M. Wenderoth;K. Engel;T. Druga;S. Loth;R. Ulbrich
我们目前的扫描隧道显微镜数据清洁银（111）表面在超高真空。驻波图案的表面状态进行了调查，研究的影响，隧道结上的恒定电流拓扑结构上的热阶跃。当在低于针尖和样品之间的温差超过几个开尔文的偏压下测量恒流形貌时，表观电阻率急剧增加。在低偏置电压和有限的温度差的恒定电流形貌不揭示真实的局域态密度的表面。表观的热电势是由在扫描样品的局域态密度时叠加到偏置电压上的空间变化的热电势引起的。借助于扫描隧道电位法，可以重建出正确的样品局域态密度。
We present scanning tunneling microscopy data on clean Ag(111) surfaces in UHV. Standing-wave patterns of the surface state are investigated to study the influence of a thermal step across the tunnel junction on constant current topographies. When constant current topographies are measured at bias voltages belowwith temperature differences of more than a few kelvins between tip and sample, the apparent corrugation is drastically increased. Constant current topographies at low bias voltages and finite temperature differences do not reveal the true local density of states of the surface. The apparent corrugation is caused by a spatial varying thermovoltage superimposed to the bias voltage while scanning the sample’s local density of states. With the help of scanning tunneling potentiometry, the correct local density of states of the sample can be reconstructed.