Related papers: Chiral phonons in binary compounds $A$Bi ($A$ = K,…

Recently discovered magnetic topological insulators $T$Bi$_{2}$Te$_{4}$ ($T=$Mn, Fe) crystallize into the $R\bar{3}m$ rhombohedral structure and exhibit the antiferromagnetic order. Here, we discuss the lattice dynamics of these compounds…

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…

Phonons are quanta of lattice vibrations, and their modes (linear, circular, or stationary) are symmetry-determined. Circularly polarized phonons, possessing nonzero angular momentum (AM), have drawn widespread attention recently. Despite…

Recent experimental evidences point to rotation symmetry breaking superconductivity in doped Bi$_2$Se$_3$, where the relevant order parameter belongs to a two-component odd-parity representation $E_u$ of the crystal point group. The $E_u$…

Chiral phonons have been proposed to be involved in various physical phenomena, yet the chirality of molecular normal modes has not been well defined mathematically. Here we examine two approaches for assigning and quantifying the chirality…

Chiral phonons are the ones with nonzero polarization and can be observed only via a selective coupling with valley electrons and circularly polarized photons. In such process, a new physical quantity, i.e., pseudo-angular momentum (PAM),…

Quasiparticles describe collective excitations in many-body systems, and their symmetry classification is of fundamental importance because they govern physical processes on various timescales, e.g., excited states, transport phenomena, and…

We have developed a microscopic theory on phonon energy dispersion in chiral crystals within a harmonic approximation. One of the main issues is about the splitting of sound velocity of acoustic phonons with opposite ``crystal'' angular…

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…

Truly chiral phonons are lattice eigenmodes that combine broken mirror symmetry with circular atomic motion. They can mediate angular-momentum-selective interactions in quantum materials, yet directly resolving both their chirality and…

Chiral vibrations are studied with the RPA plus self-consistent tilted axis cranking formalism in the A=135 region. In this method chiral vibrations appear as a precursor to the static chiral regime. The properties of the RPA phonons are…

The concept of chirality is of great relevance in nature, from chiral molecules such as sugar to parity transformations in particle physics. In condensed matter physics, recent studies have demonstrated chiral fermions and their relevance…

Using first-principles density functional theory calculations, we investigate a family of stable two-dimensional crystals with chemical formula $A_2B_2$, where $A$ and $B$ belong to groups IV and V, respectively ($A$ = C, Si, Ge, Sn, Pb;…

Chirality characterizes the asymmetry between a structure and its mirror image and underlies a wide range of chiral functionalities. In crystallographically chiral materials, phonons with non-zero linear momentum $\textbf{k}$ can acquire a…

The notion that phonons can carry pseudo-angular momentum has become popular in the last decade, with recent research efforts highlighting phonon chirality, Berry curvature of phonon band structure, and the phonon Hall effect. When a phonon…

We have studied the magnetic response of transverse optical phonons in Pb$_{1-x}$Sn$_{x}$Te films. Polarization-dependent terahertz magnetospectroscopy measurements revealed Zeeman splittings and diamagnetic shifts, demonstrating that these…

We present a microscopic theory of chirality-induced orbital selectivity (CIOS) in helical crystals, in which truly chiral phonons selectively transfer angular momentum to electronic orbital degrees of freedom. For a threefold helical…

Two-dimensional (2D) magnetic systems possess versatile magnetic order and can host tunable magnons carrying spin angular momenta. Recent advances show angular momentum can also be carried by lattice vibrations in the form of chiral…

We report a detailed first-principles study of the structural, electronic and vibrational properties of the superconducting C$_{32}$ phase of the ternary alloy CaAl$_{2-x}$Si$_x$, both in the experimental range $0.6 \leq x \leq 1.2$, for…

Chiral bound states in the continuum (BICs) are confined photonic modes with infinite quality factors and chiral response, offering significant potential for chiral optics. Although a novel type of spin-orbital-locking chiral BIC was…