Universal magnetic-field-driven metal-insulator-metal transformations in graphite and bismuth
Universal magnetic-field-driven metal-insulator-metal transformations in graphite and bismuth
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DOI：
10.1103/physrevb.73.165128
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发表时间：
2006-04-01
影响因子：
3.7
通讯作者：
Moehlecke, S
中科院分区：
文献类型：
--
作者：
Kopelevich, Y;Pantoja, JCM;Moehlecke, S
外加磁场诱导石墨和菱面体铋中的金属-绝缘体和重入绝缘体-金属相变。对于这些半金属，在磁场-温度(B-T)平面上绘制的相应相变边界几乎重合，并且可以用类似于(B-B-c)(Kappa)的幂定律T来描述，其中B-c是T=0且kappa=0.45+/-0.05的临界场。我们证明了绝缘体-金属-绝缘体(I-M-I)相变发生在朗道能级量子化区域，并说明了具有中等各向异性的石墨样品中的绝缘体-金属相变是如何转变为与强各向异性准二维石墨样品中的量子霍尔效应有关的一系列I-M-I相变的。我们讨论了超导和激子关联与观察到的现象的可能耦合，以及与M-I和I-M变换相关的量子相变的特征。
Applied magnetic field induces metal-insulator and reentrant insulator-metal transitions in both graphite and rhombohedral bismuth. The corresponding transition boundaries plotted on the magnetic field-temperature (B-T) plane nearly coincide for these semimetals and can be best described by power laws T similar to(B-B-c)(kappa), where B-c is a critical field at T=0 and kappa=0.45 +/- 0.05. We show that insulator-metal-insulator (I-M-I) transformations take place in the Landau level quantization regime and illustrate how the insulator-metal transformation in graphite samples with a moderate anisotropy transforms into a cascade of I-M-I transitions, related to the quantum Hall effect in strongly anisotropic, quasi-two-dimensional graphite samples. We discuss the possible coupling of superconducting and excitonic correlations with the observed phenomena, as well as the signatures of quantum phase transitions associated with the M-I and I-M transformations.