Spiral twisting offers additional opportunities for controlling the loss, dispersion, and polarization state of light in optical fibers with noncircular guiding cores. Here, we report an effect that appears in continuously twisted photonic crystal fiber. Guided by the helical lattice of hollow channels, cladding light is forced to follow a spiral path. This diverts a fraction of the axial momen...

To know the properties of a particle or a wave, one should measure how its energy changes with its momentum. The relation between them is called the dispersion relation, which encodes essential information of the kinetics. In a magnet, the wave motion of atomic spins serves as an elementary excitation, called a spin wave, and behaves like a fictitious particle. Although the dispersion relation ...

Rotational superradiance affects the dynamics of many rotating systems in nature, through either stimulated or spontaneous extraction energy and angular momentum. By now, this process is well-studied relativistic setting, where are intrinsically dispersion-free. In condensed matter systems, however, dispersion an unavoidable aspect description for short wavelength modes. For these how might one...

Phonon angular momentum in chiral materials has been widely studied spintronics and condensed matter physics. In crystals, this is not the conserved quantity contrast to pseudo-angular momentum. To highlight point understand behavior of momentum, we reexamined phonon dispersion theory based on irreducible representation helix found distinction these originated from chirality.

Heterostructures such as resonant tunneling diodes, quantum well photodetectors and lasers, and cascade lasers break the symmetry of the crystalline lattice. Such break in lattice symmetry causes a strong interaction of heavy-, lightand split-off hole bands. A resonant tunneling diode is used as a vehicle to study hole transport in heterostructures including the subband dispersion transverse to...

Spin-lattice relaxation rates (R(1H) and R(1F)) of two nuclear species ((1)H and (19)F) are measured at different temperatures in the isotropic phase of a liquid crystal (4(')-butoxy-3(')-fluoro-4-isothiocyanatotolane-4OFTOL), over a wide range of Larmor frequency (10 kHz-50 MHz). Their dispersion profiles are found to be qualitatively very different, and the R(1F) in particular shows significa...