Electron tunnelling phase time and dwell time through an associated delta potential barrier

摘要

The electron tunnelling phase time τp and dwell time τD through an associated delta potential barrier U(x) = ξδ(x)are calculated and both are in the order of 10-17 - 10-16s. The results show that the dependence of the phase time on the delta barrier parameter ξ can be described by the characteristic length lc = h2/meξ and the characteristic energy Ec = meξ2/H2 of the delta barrier, where me is the electron mass, Ic and Ec are assumed to be the effective width and height of the delta barrier with lcEc= ξ, respectively. It is found that τD reaches its maximum and τD = τP as the energy of the tunnelling electron is equal to Ec/2, i.e. as lc = λDB, λDB is de Broglie wave length of the electron.