Pseudo Landau levels, negative strain resistivity, and enhanced thermopower in twisted graphene nanoribbons

Shi, Zheng; Lu, Hai‐Zhou; Li, Tianyu

doi:10.1103/physrevresearch.3.033139

Cited by 6 publications

(2 citation statements)

References 102 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In graphene systems, strain or twist can create a pseudomagnetic field that imitates an actual magnetic field and produces a zero magnetic field equivalent of the Landau levels, known as pseudo-Landau levels (PLLs). PLLs are an important tool for studying the quantum Hall effect in theory [1][2][3] and discovering novel electronic states beyond actual Landau levels in experiments [4,5]. Recently, the discovery of correlated insulating states and the possibility of unconventional superconductivity in moiré graphene systems has generated magnetic field [10,23], which breaks time-reversal symmetry and induces a large orbital magnetic moment [27,28].…”

Section: Introductionmentioning

confidence: 99%

Impurity effects on the zeroth pseudo-Landau level in twisted bilayer graphene

Liu

Xie

2023

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We theoretically studied the impurity effects on the zeroth pseudo-Landau level representation of the flat band in a twisted bilayer graphene system. Our research investigates the impact of both short-range and long-range charged impurities on the pseudo-Landau level using the self-consistent Born approximation and random phase approximation. Our findings indicate that short-range impurities have a significant effect on the broadening of the flat band due to impurity scattering. In contrast, the impact of long-range charged impurities on the broadening of the flat band is relatively weak, and the primary impact of the Coulomb interaction is the splitting of the pseudo-Landau level degeneracy when a certain purity condition is satisfied. As a result, spontaneous ferromagnetic flat bands with nonzero Chern numbers emerge. Our work sheds light on the effect of impurities on the quantum Hall plateau transition in twisted bilayer graphene systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Impurity effects on the zeroth pseudo-Landau level in twisted bilayer graphene

Liu

Xie

2023

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…Such strain displaces the Dirac cones in a space-dependent fashion analogous to magnetic fields and can thus induce lowenergy pseudo-Landau levels that support quantum oscillations [27,28] as well as the chiral anomaly and the associated chiral magnetic effect [29,30]. In the simplest and most flexible Dirac material -graphene, the experimentally implementable strain can be as large as 27% [31,32], and may be of various patterns, such as bend [33][34][35], twist [31,36], and other simple uniaxial ones [37,38].…”

mentioning

confidence: 99%

Analytic solution to pseudo-Landau levels in strongly bent graphene nanoribbons

Li¹,

Moessner²,

Lu³

2021

Preprint

Self Cite

View full text Add to dashboard Cite

Nonuniform elastic strain is known to induce pseudo-Landau levels in Dirac materials. But these pseudo-Landau levels are hardly resolvable in an analytic fashion when the strain is strong, because of the emerging complicated space dependence in both the strain-modulated Fermi velocity and the strain-induced pseudomagnetic field. We analytically characterize the solution to the pseudo-Landau levels in experimentally accessible strongly bent graphene nanoribbons, by treating the effects of the nonuniform Fermi velocity and pseudomagnetic field on equal footing. The analytic solution is detectable through the angle-resolved photoemission spectroscopy (ARPES) and allows quantitative comparison between theories and various transport experiments, such as the Shubnikov-de Haas oscillation in the complete absence of magnetic fields and the negative strain-resistivity resulting from the valley anomaly. The analytic solution can be generalized to twisted two-dimensional materials and topological materials and will shed a new light on the related experimental explorations and straintronics applications.

show abstract