RESONANT TUNNELING IN SEMICONDUCTOR DOUBLE BARRIERS
RESONANT TUNNELING IN SEMICONDUCTOR DOUBLE BARRIERS
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DOI：
10.1063/1.1655067
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发表时间：
1974-01-01
影响因子：
4
通讯作者：
TSU, R
中科院分区：
文献类型：
--
作者：
CHANG, LL;ESAKI, L;TSU, R
在具有夹在两个GaAlAs势垒之间的薄GaAs的双势垒结构中已经观察到电子的共振隧穿。共振表现为在势阱的准稳态附近的电压处的隧穿电流中的峰或驼峰。这种结构是用分子束外延技术制造的，它可以产生非常光滑的薄膜和界面，电子波通过势垒的共振传输现象是一种常见的现象。一维晶体的Kronig-Penney模型由一系列势垒组成，这些势垒表现出由衰减的禁带分隔的完全透射的允许带。Bohm 1和Iogansen 2用WKB近似和Kane 3用波函数匹配的方法讨论了双势垒的情况。最近，大津和江崎4在隧道形式主义的框架内处理了多个势垒的一般情况，考虑了现实的三维问题。通过假设电子的总能量和横截隧穿方向的动量守恒，计算了隧穿电流的电压依赖性。5共振显示，在这样的施加电压，电极的费米能量与准稳态的势阱相一致，引起电流最大值。然而，人们普遍认为，这种效应是非常难以实现的实验，因为结构波动的潜力和厚度。另一方面，场发射电子通过金属表面吸附的原子的共振隧穿已经被Gadzuk 6处理，以解释Plummer和Young的实验结果。7
Resonant tunneling of electrons has been observed in double-barrier structures having a thin GaAs sandwiched between two GaAlAs barriers. The resonance manifests itself as peaks or humps in the tunneling current at voltages near the quasistationary states of the potential well. The structures have been fabricated by molecular beam epitaxy which produces extremely smooth films and interfaces.The phenomenon of resonant transmission of electron waves through potential barriers is a familiar one. The Kronig-Penney model of a one-dimensional crystal consists of a series of barriers which exhibits allowed bands of perfect transmission separated by forbidden bands of attenuation. The situation of double barriers has been discussed by Bohm 1 and Iogansen2 using the WKB approximation and by Kane3 using the method of wave-function matching. Recently, Tsu and Esaki4 have treated the general case of multiple barriers in the framework of tunneling formalism, conSidering the realistic three-dimensional problem. The voltage dependence of the tunneling current has been calculated by assuming the conservations of the total electron energy and its momentum transverse to the direction of tunneling. 5 Resonance is shown to give rise to current maxima at such applied voltages that the Fermi energy of the electrode coincides with the quasistationary states of the potential well. However, it has been generally accepted that this kind of effect is very difficult to realize experimentally because of structural fluctuations in both the potentials and the thicknesses. On the other hand, resonant tunneling of field-emitted electrons through atoms absorbed on metal surfaces has been treated by Gadzuk6 to interpret the experimental results by Plummer and Young. 7