Magnetoquantum oscillations and confinement effects in arrays of 270-nm-diameter bismuth nanowires
Magnetoquantum oscillations and confinement effects in arrays of 270-nm-diameter bismuth nanowires
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DOI：
10.1103/physrevb.67.245317
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发表时间：
2003-06
影响因子：
3.7
通讯作者：
T. Huber;K. Celestine;M. Graf
中科院分区：
文献类型：
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作者：
T. Huber;K. Celestine;M. Graf
我们提出了一个270 nm直径的铋纳米线阵列嵌入在氧化铝基质中的电输运性质的研究，这是加盖层的散装铋，以产生一个非常低的接触电阻。在较宽的温度范围（1.8-300 K）和磁场范围（-8-8 T）内测量了Bi纳米线的纵向和横向电阻。在低磁场下，纵向磁电阻表现出场周期调制，其周期与Aharonov-Bohm“回音壁”模式的理论预测一致;在高磁场下，当载流子回旋半径小于金属丝直径时，我们观察到空穴和电子的Shubnikov-de哈斯振荡.这些代表了对高密度纳米线阵列中磁量子振荡的详细研究。总的来说，空穴周期增加了5%，载流子密度降低了13%，从散装Bi的值，这是一致的，最近的理论估计的约束对载流子的费米面的影响。
We present a study of the electrical transport properties of 270-nm-diameter bismuth nanowire arrays embedded in an alumina matrix which are capped with layers of bulk Bi to produce a very low contact resistance. The resistance of the Bi nanowires has been measured over a wide range of temperatures (1.8-300 K) and magnetic fields (-8-8 T) for the longitudinal and transverse orientation. At low magnetic fields, the longitudinal magnetoresistance exhibits field-periodic modulations whose periods are consistent with theoretical predictions for the Aharonov-Bohm "whispering gallery" modes of electrons with long mean free path. At high magnetic fields, as the carrier cyclotron radius becomes smaller than the wire diameter, we observe Shubnikov-de Haas oscillations associated with both holes and electrons. These represent a detailed study of magnetoquantum oscillations in high-density nanowire arrays. Overall, the hole periods are increased by 5% and the carrier density is decreased by 13% from the values for bulk Bi, which is consistent with recent theoretical estimates of the effect of confinement on the carrier's Fermi surface.