Magnetoresistance of a two-dimensional electron gas in a strong periodic potential.
Magnetoresistance of a two-dimensional electron gas in a strong periodic potential.
复制标题
强周期性电势下二维电子气的磁阻。
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
Wilkinson
中科院分区：
文献类型：
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作者：
Beton;Alves;Main;Eaves;Dellow;Henini;Hughes;Beaumont;Wilkinson
本文研究了二维电子气在变幅周期势作用下的磁电阻效应。周期为300 nm的周期性电势是利用沉积在图案化抗蚀剂层上的栅极产生的，并且其幅度由栅极电压控制。在低栅压下，观察到反向磁场中的两系列周期振荡。在低磁场下，一个系列是由于周期势，另一个是通常的Shubnikovchar 21 {}de哈斯振荡。小的栅极电压的应用产生低场振荡的幅度的增加，随后随着栅极电压进一步增加，这些振荡被淬灭。此外，低场正磁阻的产生，变得更大的栅极电压的增加。这些影响内的半经典模型的电子输运解释。此外，Shubnikovchar 21 {}de哈斯振荡随着电势的振幅增加而淬灭。这可以用朗道能级的加宽来解释。
We have investigated the magnetoresistance of a two-dimensional electron gas subjected to a periodic potential of variable amplitude. The periodic potential, of period 300 nm, is generated with use of a gate deposited over a layer of patterned resist, and its amplitude is controlled by the gate voltage. At low gate voltages, two series of oscillations periodic in inverse magnetic field are observed. One series, at low magnetic field, is due to the periodic potential and the other is the usual Shubnikovchar21{}de Haas oscillations. The application of a small gate voltage generates an increase in the amplitude of the low-field oscillations, followed by a quenching of these oscillations as the gate voltage is increased further. In addition, a low-field positive magnetoresistance is generated, becoming larger with increasing gate voltage. These effects are explained within a semiclassical model of electron transport. Also the Shubnikovchar21{}de Haas oscillations quench as the amplitude of the potential increases. This is explained in terms of a broadening of the Landau levels.