相关论文: Anomalous thermal expansion and chiral phonons in …
Anomalous thermal expansion behaviour of several open frame-work compounds has been extensively investigated using the techniques of inelastic neutron scattering and lattice dynamics. These compounds involve increasing level of structural…
In order to identify and quantitatively analyze the anharmonicity of phonons relevant to the anomalous thermal expansion in the Ih phase of ice, we performed neutron inelastic scattering measurements of the phonon spectrum as a function of…
The class of layered 3D-topological insulators have shown intriguingly anomalous temperature dependence in their thermal expansion coefficients. It was proposed that stacking faults are the origin of the observed anomalous thermal…
We have investigated the anisotropic thermal expansion of graphite using ab-initio calculation of lattice dynamics and anharmonicity of the phonons, which reveal that the negative thermal expansion (NTE) in the a-b plane below 600 K and…
Black Phosphorus (BP) has gained renewed attention due to its singular anisotropic electronic and optical properties that might be exploited for a wide range of technological applications. In this respect, the thermal properties are…
Torsional strain in Weyl semimetals excites a unidirectional chiral density wave propagating in the direction of the torsional vector. This gapless excitation, named the chiral sound wave, is generated by a particular realization of the…
All phonons in a single crystal of NaBr were measured by inelastic neutron scattering at temperatures of 10, 300 and 700 K. Even at 300 K the phonons, especially the longitudinal-optical (LO) phonons, showed large shifts in frequencies, and…
The thermal expansion behavior of metal fluorides can be tuned by choosing appropriate metal cation. We present ab-initio lattice dynamical studies on the metal fluorides (CaZrF6, MgZrF6 and SrZrF6) and identify the anharmonic phonon modes…
The concept of chirality makes ubiquitous appearance in nature. Particularly, both a structure and its collective excitations may acquire well defined chiralities. In this work, we reveal an intrinsic connection between the chiralities of a…
We investigate linear and nonlinear transverse planar transport phenomena (viz. linear and nonlinear Hall and Nernst coefficients) induced by chiral anomaly in three-dimensional spin-orbit coupled metallic systems. Unlike Weyl semimetals,…
An anisotropic lattice anomaly near the superconducting transition temperature, Tc, was observed in MgB2 by high-resolution neutron powder diffraction. The a-axis thermal expansion becomes negative near Tc, while the c-axis thermal…
We propose a mechanism to obtain chiral phonon-like excitations from the bond-dependent magnetoelastic couplings in the absence of out-of-plane magnetization and magnetic fields. By mapping the hybrid excitation to its phononic analog, we…
The theory of anomalous Hall effect for the heat transfer in a paramagnetic dielectric, discovered experimentally in [1], is developed. The appearance of the phonon heat flux normal to both the temperature gradient and the magnetic field is…
Recent experiments suggest that the conditions for ferromagnetic order in, e.g., magnetite, can be modified by adsorption of chiral molecules. Especially, the coercivity of magnetite was increased by nearly 100 \%, or 20 times the earth…
Features of the phonon spectrum of a chiral crystal are examined within the micropolar elasticity theory. This formalism accounts for not only translational micromotions of a medium but also rotational ones. It is found that there appears…
The chiral anomaly is the predicted break down of chiral symmetry in a Weyl semimetal with monopoles of opposite chirality when an electric field parallel to a magnetic field is applied. It occurs because of charge pumping from a positive…
We investigate detailed lattice dynamics of copper halides CuX (X=Cl, Br, I) using neutron inelastic scattering measurements and ab-initio calculations aimed at a comparative study of their thermal expansion behavior. We identify the low…
Thermal behavior of effective, chiral condensate-dependent $U_A(1)$ anomaly couplings is investigated using the functional renormalization group approach in the $N_f = 3$ flavor meson model. We derive flow equations for anomaly couplings…
We have carried out temperature-dependent x-ray diffraction and Raman scattering experiments on powder $Cs_3Bi_2Br_9$. Trigonal to monoclinic structural transition at around 95 K is discussed and shown to be driven by the softening of the…
A detailed temperature and pressure investigation on BiGdO$_{3}$ is carried out by means of dielectric constant, piezoelectric current, polarization-electric field loop, Raman scattering and x-ray diffraction measurements. Temperature…