Theory of metal-insulator transitions in graphite under high magnetic field
Theory of metal-insulator transitions in graphite under high magnetic field
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高磁场下石墨金属-绝缘体转变理论
DOI：
10.1103/physrevb.98.205121
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发表时间：
2018-02
影响因子：
3.7
通讯作者：
Ryuichi Shindou
中科院分区：
文献类型：
--
作者：
Zhiming Pan;Xiao-Tian Zhang;Ryuichi Shindou
在低温下，强磁场作用下的石墨在准量子极限下表现出连续的金属-绝缘体（MI）相变和凹入的绝缘体-金属（IM）相变。在本文中，我们确定低$T$绝缘相作为激子绝缘体与自旋无序。我们首先指出，石墨在相关的领域制度是在电荷中性区，电子和空穴密度相互补偿。在此基础上，我们引入了具有电子袋和空穴袋的相互作用电子模型，并列举了电荷中性条件下可能的umklapp散射过程。采用有效玻色子理论的电子模型和重整化群（RG）分析的玻色子理论，我们表明，存在临界相互作用强度以上的umklapp过程成为相关的和系统进入激子绝缘体阶段与长程有序的自旋超导相场（“自旋激子绝缘体”）。我们认为，当一对电子和空穴口袋的尺寸变小，自旋超导相的量子涨落变得更大，不稳定的激子绝缘体相，导致重入IM过渡。我们还表明，奇宇称激子对之间的电子和空穴口袋重建表面手征费米弧状态的电子和空穴到一个2维螺旋表面状态与一个无隙的狄拉克锥。我们讨论了场和温度依赖性的面内电阻的表面输运通过这些表面状态。
Graphite under high magnetic field exhibits consecutive metal-insulator (MI) transitions as well as re-entrant insulator-metal (IM) transition in the quasi-quantum limit at low temperature. In this paper, we identify the low-$T$ insulating phases as excitonic insulators with spin nematic orderings. We first point out that graphite under the relevant field regime is in the charge neutrality region, where electron and hole densities compensate each other. Based on this observation, we introduce interacting electron models with electron pocket(s) and hole pocket(s) and enumerate possible umklapp scattering processes allowed under the charge neutrality. Employing effective boson theories for the electron models and renormalization group (RG) analyses for the boson theories, we show that there exist critical interaction strengths above which the umklapp processes become relevant and the system enter excitonic insulator phases with long-range order of spin superconducting phase fields ("spin nematic excitonic insulator"). We argue that, when a pair of electron and hole pockets get smaller in size, a quantum fluctuation of the spin superconducting phase becomes larger and destabilizes the excitonic insulator phases, resulting in the re-entrant IM transitions. We also show that an odd-parity excitonic pairing between the electron and hole pockets reconstruct surface chiral Fermi arc states of electron and hole into a 2-dimensional helical surface state with a gapless Dirac cone. We discuss field- and temperature-dependences of in-plane resistance by surface transports via these surface states.
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影响因子：
--
作者：
E. Fenton
通讯作者：
E. Fenton
影响因子：
--
作者：
G. Dresselhaus;M. Dresselhaus
通讯作者：
G. Dresselhaus;M. Dresselhaus
影响因子：
10.9
作者：
DRESSELHAUS, GF;DRESSELHAUS, MS;MAVROIDES, JG
通讯作者：
MAVROIDES, JG
DOI：
10.1103/physrevb.50.1351
发表时间：
1993-10
期刊：
Physical review. B, Condensed matter
影响因子：
--
作者：
Houghton;Kwon;Marston
通讯作者：
Houghton;Kwon;Marston
影响因子：
8.6
作者：
Fauque, Benoit;LeBoeuf, David;Behnia, Kamran
通讯作者：
Behnia, Kamran