Related papers: Chiral valley phonons and flat phonon bands in moi…
Chiral phonons have been identified in several chiral crystals, primarily in those with trigonal symmetry and threefold screw axes. In this study, chiral phonons in CrSi$_2$, a chiral crystal with a sixfold helical structure, were…
Ultraflat bands in twisted bilayers of two-dimensional materials have potential to host strong correlations, including the Mott-insulating phase at half-filling of the band. Using first principles density functional theory calculations, we…
We theoretically investigated the chiral phonons of honeycomb-type bilayer Wigner crystals recently discovered in van der Waals structures of layered transition metal dichalcogenides. These chiral phonons can emerge under the inversion…
Moir\'e lattices have served as the ideal quantum simulation platform for exploring novel physics due to the flat electronic bands resulting from the long wavelength moir\'e potentials. However, the large sizes of this type of system…
We study the influence of strong spin-orbit interaction on the formation of flat bands in relaxed twisted bilayer WSe$_2$. Flat bands, well separated in energy, emerge at the band edges for twist angles ($\theta$) near 0$^{\circ}$ and…
Chiral phonons are vibrational modes in a crystal that possess a well-defined handedness or chirality, typically found in materials that lack inversion symmetry. Here we report the discovery of chiral phonon modes in the kagome…
Chiral phonons are desirable for applications in spintronics but their generation and control remains a challenge.Here we demonstrate the emergence of truly chiral phonons from selective magnon-phonon coupling in inversion-symmetric…
Valley degrees of freedom in transition-metal dichalcogenides influence thoroughly electron-phonon coupling and its nonequilibrium dynamics. We conducted a first-principles study of the quantum kinetics of chiral phonons following…
This paper presents a mathematical and numerical analysis of the flatband wavefunctions occurring in the chiral model of twisted bilayer graphene at the "magic" twist angles. We show that the chiral model possesses an exact intra-valley…
We explore the moir\'e magnon bands in twisted bilayer magnets with next-nearest neighboring Dzyaloshinskii-Moriya interactions, assuming that the out-of-plane collinear magnetic order is preserved under weak interlayer coupling. By…
Twisted 2D materials exhibit unique vibrational modes called moir\'e phonons, which arise from the moir\'e superlattice. Here, we demonstrate atom-by-atom imaging of phasons, an ultrasoft class of moir\'e phonons in twisted bilayer WSe2.…
Twisted bilayers of transition metal dichalcogenides (TMDC) form moir\'e superlattices resulting in moir\'e minibands in momentum space and hosting localized excitons in real space. While moir\'e superlattices provide access to Mott-Hubbard…
We discover chiral phonons at the lowest-energy bands in moir\'e superlattices. The moir\'e chiral phonons we uncover are the collective excitations of the stacking domains. Their origin is uniquely attributed to the stacking configurations…
We theoretically studied the phonon properties of the triangular-, stripe- and honeycomb-type electronic crystals recently found in two-dimensional semiconductor moir\'e patterns. By analyzing the phonon dispersions, we found the…
We report planar tunneling spectroscopy measurements on metal-WSe$_2$-twisted bilayer graphene heterostructures across a broad range of gate and bias voltages. The observed experimental features are attributed to phonon-assisted tunneling…
Two-dimensional moir\'e materials offer a powerful, twist-tunable platform for engineering electronic bands and correlations, though most studies to date have focused on small twist angles where flat bands arise from symmetry-pinned…
We develop a low-energy continuum model for phonons in twisted moir\'e bilayers, based on a configuration-space approach. In this approach, interatomic force constants are obtained from density functional theory (DFT) calculations of…
Recent experiments in twisted bilayer transition-metal dichalcogenides have revealed a variety of strongly correlated phenomena. To theoretically explore their origin, we combine here ab initio calculations with correlated model approaches…
We study the in-plane acoustic phonons in twisted bilayer graphenes using the effective continuum approach. We calculate the phonon modes by solving the continuum equation of motion for infinitesimal vibration around the static relaxed…
Phonon chirality has attracted intensive attention since it breaks the traditional cognition that phonons are linear propagating bosons. This new quasiparticle property has been extensively studied theoretically and experimentally. However,…