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arXiv · 2312.16042

Robust $T$-Linear Resistivity due to SU(4) Valley + Spin Fluctuation Mechanism in Magic Angle Twisted Bilayer Graphene

Daisuke Inoue·Seiichiro Onari·Hiroshi Kontani
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Abstract

In the magic angle twisted bilayer graphene (MATBG), non-Fermi liquid like transport phenomena are universally observed. To understand their origin, we perform the self-consistent analysis of the self-energy due to SU(4) valley + spin fluctuations induced by the electron-electron correlation. In the SU(4) fluctuation mechanism, the fifteen channels of fluctuations contribute additively to the self-energy. Therefore, the SU(4) fluctuation mechanism gives much higher electrical resistance than the spin fluctuation mechanism. By the same reason, SU(4) fluctuations of intermediate strength provide $T$-linear resistivity down to $\sim1$K. Interestingly, the $T$-linear resistivity is robustly realizedfor wide range of electron filling, even away from the van-Hove filling. This study provides a strong evidence for the importance of electron-electron correlation in MATBG.

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Daisuke Inoue, Seiichiro Onari, Hiroshi Kontani. 2023-12-26. Robust $T$-Linear Resistivity due to SU(4) Valley + Spin Fluctuation Mechanism in Magic Angle Twisted Bilayer Graphene. https://doi.org/10.1103/physrevb.109.205102

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