Flat bands, electron interactions and magnetic order in magic-angle mono-trilayer graphene

Goodwin, Zachary A. H.; Klebl, Lennart; Vitale, Valerio; Liang, Xia; Gogtay, Vivek; van Gorp, Xavier; Kennes, Dante M.; Mostofi, Arash A.; Lischner, Johannes

doi:10.48550/arxiv.2105.12641

Cited by 3 publications

(3 citation statements)

References 70 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bands reported in figure 9 are in reasonable agreement with those in [58]. As in the two previous cases, and similar to related materials [65], even for a small dielectric constant the Hartree potential only slightly modifies the shape and bandwidth of the narrow bands.…”

Section: Band Structuresupporting

confidence: 86%

Narrow bands, electrostatic interactions and band topology in graphene stacks

et al. 2021

View full text Add to dashboard Cite

The occurrence of superconducting and insulating phases is well-established in twisted graphene bilayers, and they have also been reported in other arrangements of graphene layers. We investigate three such arrangements: untwisted AB bilayer graphene on an hBN substrate, two graphene bilayers twisted with respect to each other, and a single ABC stacked graphene trilayer on an hBN substrate. Narrow bands with different topology occur in all cases, producing a high density of states which enhances the role of interactions. We investigate the effect of the long range Coulomb interaction, treated within the self consistent Hartree–Fock approximation. We find that the on-site part of the Fock potential strongly modifies the band structure at charge neutrality. The Hartree part does not significantly modify the shape and width of the bands in the three cases considered here, in contrast to the effect that such a potential has in twisted bilayer graphene.

show abstract

Section: Band Structuresupporting

confidence: 86%

Narrow bands, electrostatic interactions and band topology in graphene stacks

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In this case, calculations of the electronic structure in the absence of this mirror symmetry shows hybridized monolayer and twisted bilayer features [3,[23][24][25][26][27]. The effect of electron-electron interactions have also been considered [24][25][26][27][28][29][30], as well as the role of external magnetic fields [31].…”

mentioning

confidence: 99%

Band Structure and Superconductivity in Twisted Trilayer Graphene

Phong,

Pantaleón,

Cea

et al. 2021

Preprint

View full text Add to dashboard Cite

We study the symmetries of twisted trilayer graphene's band structure under various extrinsic perturbations, and analyze the role of long-range electron-electron interactions near the first magic angle. The electronic structure is modified by these interactions in a similar way to twisted bilayer graphene. We analyze electron pairing due to long-wavelength charge fluctuations, which are coupled among themselves via the Coulomb interaction and additionally mediated by longitudinal acoustic phonons. We find superconducting phases with either spin singlet/valley triplet or spin triplet/valley singlet symmetry, with critical temperatures of up to a few Kelvin for realistic choices of parameters.

show abstract

“…A particularly promising platform for observing and manipulating chiral phonons are twisted bilayers of two-dimensional (2D) materials. Since the discovery of flat electronic bands in twisted bilayer graphene [20], such moiré materials have emerged as rich systems to investigate the properties of correlated electrons, excitons and phonons [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. For example, at small twist angles phonon properties are significantly modified as a consequence of large atomic re-constructions [38,41,42] which result in the localization of incipient phason modes [43] and optical phonon modes [43][44][45][46][47][48][49].…”

mentioning

confidence: 99%

Chiral valley phonons and flat phonon bands in moiré materials

Maity,

Mostofi,

Lischner

2021

Preprint

Self Cite

View full text Add to dashboard Cite

We investigate the chirality of phonon modes in twisted bilayer WSe2. We demonstrate distinct chiral behavior of the K/K valley phonon modes for twist angles close to 0 • and close to 60 • . Moreover, we discover two sets of well-separated chiral valley modes in moiré lattices for angles close to 60 • . These emergent moiré chiral valley phonons originate from inversion symmetry breaking at the moiré scale. We also find similar emergent chiral modes in moiré patterns of strain-engineered bilayer WSe2 and MoSe2/WSe2 heterostructure. Furthermore, we observe the flattening of bands near the phononic band-gap edges for a broad range of twist angles in twisted bilayer WSe2. Our findings, which are expected to be generic for moiré systems composed of two-dimensional materials that break inversion symmetry, are relevant for understanding electron-phonon and exciton-phonon scattering, and for designing phononic crystals to mimic behaviors of electrons in moiré materials.

show abstract

Flat bands, electron interactions and magnetic order in magic-angle mono-trilayer graphene

Cited by 3 publications

References 70 publications

Narrow bands, electrostatic interactions and band topology in graphene stacks

Narrow bands, electrostatic interactions and band topology in graphene stacks

Band Structure and Superconductivity in Twisted Trilayer Graphene

Chiral valley phonons and flat phonon bands in moiré materials

Contact Info

Product

Resources

About