Metal-insulator-like behavior in semimetallic bismuth and graphite
Metal-insulator-like behavior in semimetallic bismuth and graphite
复制标题
DOI：
10.1103/physrevlett.94.166601
复制
发表时间：
2005-04-29
影响因子：
8.6
通讯作者：
Hebard, AF
中科院分区：
文献类型：
--
作者：
Du, X;Tsai, SW;Hebard, AF
当高质量的铋或石墨晶体被置于沿着c轴（铋的三角轴）的磁场中，温度降低时，电阻会像绝缘体中的电阻一样增加，但随后会饱和。我们表明，结合不寻常的特点，具体到半金属，即，低载流子密度、小有效质量、高纯度以及相等数量的电子和空穴（补偿），产生了三种特征能量尺度的独特排序和间隔，这不仅是半金属所特有的，而且伴随着为观察表观场致金属-绝缘体行为提供了宽窗口。使用磁输运和霍尔测量，这种不寻常的行为的细节被捕获与传统的多带模型，从而确认占领传统金属和半导体之间的一个独特的利基由半金属。
When high quality bismuth or graphite crystals are placed in a magnetic field directed along the c axis (trigonal axis for bismuth) and the temperature is lowered, the resistance increases as it does in an insulator but then saturates. We show that the combination of unusual features specific to semimetals, i.e., low carrier density, small effective mass, high purity, and an equal number of electrons and holes (compensation), gives rise to a unique ordering and spacing of three characteristic energy scales, which not only is specific to semimetals but which concomitantly provides a wide window for the observation of apparent field-induced metal-insulator behavior. Using magnetotransport and Hall measurements, the details of this unusual behavior are captured with a conventional multiband model, thus confirming the occupation by semimetals of a unique niche between conventional metals and semiconductors.