Spectral features of inelastic electron transport via a localized state
Spectral features of inelastic electron transport via a localized state
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通过局域态非弹性电子传输的光谱特征
DOI：
10.1103/physrevb.68.205406
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发表时间：
2003
影响因子：
3.7
通讯作者：
H. Ueba
中科院分区：
文献类型：
--
作者：
T. Mii;S. Tikhodeev;H. Ueba
本文采用双通道Newns-Anderson哈密顿量，研究了电子在非平衡电子分布下通过局域态和振动自由度耦合的输运光谱性质。我们的模型可以应用于研究电子通过原子线的传输，电导通过一个单分子桥夹在两个电极之间，也非弹性隧道光谱的单个吸附与扫描隧道显微镜。在这些现象中预期的一个共同的关键特征是具有晶格或分子振动的非弹性散射。计算了定域能级的态密度ρ a和总电流d2 I/dV 2对偏压的二阶导数，阐明了非弹性散射在ρ a和d2 I/dV 2中的表现.研究发现，局域态隧穿电子的寿命和两电极间电子的虚激发和局域态的停留时间这两个不同的时间尺度对d2 I/dV 2谱的各种特征起着重要的作用.
A theory of spectral properties of electron transport via a localized state coupled with a vibrational degree of freedom is presented using a two-channel Newns-Anderson Hamiltonian with a nonequilibrium electron distribution. Our model can be applied to a study of electronic transport through an atomic wire, conductance via a single molecule bridge sandwiched between two electrodes, and also inelastic tunneling spectroscopy of single adsorbates with scanning tunneling microscope. A common key feature expected in these phenomena is an inelastic scattering with lattice or molecular vibration. The density of states ρ a of the localized level and the second derivative of the total current d 2 I/dV 2 with respect to the bias voltage are calculated in order to elucidate how the inelastic scattering manifests itself in ρ a and d 2 I/dV 2 . It is found that two different time scales associated with the lifetime of tunneling electrons in the localized state and the residence time due to virtual excitation of electrons between two electrodes and the localized state play important roles in various features of d 2 I/dV 2 spectra.