中国物理B ›› 2005, Vol. 14 ›› Issue (1): 208-211.doi: 10.1088/1009-1963/14/1/038
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
白尔隽1, 舒启清2
Bai Er-Juan (白尔隽)a, Shu Qi-Qing (舒启清)b
摘要: The electron tunnelling phase time $\tau ^{\rm p}$ and dwell time $\tau _{\rm D}$ through an associated delta potential barrier $U (x)=\xi \delta (x)$ are calculated and both are in the order of 10$^{-17} -10^{-16 }$s. The results show that the dependence of the phase time on the delta barrier parameter $\xi $can be described by the characteristic length $l_{\rm c} =\hbar^{2}/m_{\e}\xi $ and the characteristic energy $E_{\rm c}=m_{\e}\xi^{2}/\hbar^{2}$ of the delta barrier, where $m_{\e}$ is the electron mass, $l_{\rm c}$ and $E_{\rm c}$ are assumed to be the effective width and height of the delta barrier with $l_{\rm c}E_{\rm c}=\xi$, respectively. It is found that $\tau_{\rm D}$ reaches its maximum and $\tau _{\rm D}=\tau ^{\rm p}$ as the energy of the tunnelling electron is equal to $E_{\rm c}$/2, i.e.~as $l_{\rm c} =\mathchar'26\mkern-10mu\lambda _{\rm DB}$, $\mathchar'26\mkern-10mu\lambda_{\rm DB} $ is de Broglie wave length of the electron.
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