Tahir M, Vasilopoulos P
Department of Physics, College of Science, University of Hafr Al Batin, PO Box 1803, Hafr Al Batin 31991, Saudi Arabia.
J Phys Condens Matter. 2017 Oct 25;29(42):425302. doi: 10.1088/1361-648X/aa8428. Epub 2017 Aug 4.
The recent experimental realization of high-quality phosphorene leads to novel electronic and optical properties with possible new device applications due to its huge direct band gap. We study the commensurability or Weiss oscillations in monolayer phosphorene in the presence of a weak perpendicular magnetic field B and a weak and periodic, electric or magnetic one-dimensional modulation. Either modulation broadens the Landau levels into bands, whose width oscillates with B, and the oscillations appear in the electrical conductivity perpendicular to the modulation taken along the direction (x) of the smaller effective mass. Compared with the oscillations of the diffusive conductivity in a two-dimensional electron gas (2DEG) for typical electron densities [Formula: see text], the ones in phosphorene, with typical [Formula: see text], have approximately similar height but a period significantly smaller when plotted versus [Formula: see text] while plotted versus B they occur at significantly higher fields. The Shubnikov-de Haas oscillations exhibit a similar behaviour. When the modulation is taken along the direction (y) of the larger effective mass, the oscillation period is close to that of a 2DEG. For equal modulation strengths the bandwidth due to a magnetic modulation is one order of magnitude larger than that due to an electric one and the amplitude of the oscillations in the diffusive conductivity about 50 times larger. Numerical results are presented for experimentally relevant parameters.
近期高质量磷烯的实验实现，因其巨大的直接带隙而带来了新颖的电子和光学特性，具有潜在的新器件应用前景。我们研究了在存在弱垂直磁场(B)以及弱且周期性的电或磁一维调制情况下，单层磷烯中的可公度性或魏斯振荡。任何一种调制都会使朗道能级展宽为能带，其宽度随(B)振荡，并且振荡出现在沿较小有效质量方向（(x)）的垂直于调制方向的电导率中。与典型电子密度下二维电子气（2DEG）中的扩散电导率振荡相比，对于典型的[公式：见原文]，磷烯中的振荡高度大致相似，但当与[公式：见原文]绘制时周期明显更小，而与(B)绘制时它们出现在明显更高的磁场下。舒布尼科夫 - 德哈斯振荡表现出类似的行为。当调制沿较大有效质量方向（(y)）进行时，振荡周期接近二维电子气的周期。对于相等的调制强度，磁调制引起的带宽比电调制引起的带宽大一个数量级，并且扩散电导率振荡的幅度大约大50倍。给出了针对实验相关参数的数值结果。
