Two Phase Transitions Induced by a Magnetic Field in Graphite
Two Phase Transitions Induced by a Magnetic Field in Graphite
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DOI：
10.1103/physrevlett.110.266601
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发表时间：
2013-06-25
影响因子：
8.6
通讯作者：
Behnia, Kamran
中科院分区：
文献类型：
--
作者：
Fauque, Benoit;LeBoeuf, David;Behnia, Kamran
对于限制在最低朗道能级的三维电子气，人们推测了不同的不稳定性。在石墨中由强磁场引起的相变，被认为是电荷密度波，是这种不稳定性的唯一实验确定的情况。首次研究了石墨中高达80 T的磁电阻，我们发现磁场诱导了两个连续的相变，由两个不同的有序态组成，每个有序态都限制在有限的场窗口内。在这两种状态下，一个能隙打开的面外电导率和共存的一个意想不到的面内金属性的一个完整的间隙体系统。这种奇特的金属性可能会出现作为一个结果的边缘状态的运输预计发展中存在的散装差距。
Different instabilities have been speculated for a three-dimensional electron gas confined to its lowest Landau level. The phase transition induced in graphite by a strong magnetic field, and believed to be a charge density wave, is the only experimentally established case of such instabilities. Studying the magnetoresistance in graphite for the first time up to 80 T, we find that the magnetic field induces two successive phase transitions, consisting of two distinct ordered states each restricted to a finite field window. In both states, an energy gap opens up in the out-of-plane conductivity and coexists with an unexpected in-plane metallicity for a fully gap bulk system. Such peculiar metallicity may arise as a consequence of edge-state transport expected to develop in the presence of a bulk gap.