Utilization of pure spin currents not accompanied by the flow of electrical charge provides unprecedented opportunities for the emerging technologies based on the electron's spin degree of freedom, such as spintronics and magnonics. It was recently shown that pure spin currents can be used to excite coherent magnetization dynamics in magnetic nanostructures. However, because of the intrinsic no...

We study the excitation of spin waves in magnetic insulators by the current-induced spin-transfer torque. We predict preferential excitation of surface spin waves induced by an easy-axis surface anisotropy with critical current inversely proportional to the penetration depth and surface anisotropy. The surface modes strongly reduce the critical current and enhance the excitation power of the cu...

To seek high-$T_c$ pairing mechanism, many scientists have focused on the mysterious spontaneous rotational symmetry breaking above Tc, such as nematic order at $q=0$ and smectic $q\ne0$. Such exotic correlation-driven in metals has become a central issue condensed matter physics. We demonstrate emergence of orders due to orbital polarization ($n_{xz}\ne n_{yz}$) correlated intersite hopping (=...

We experimentally demonstrate that the spin-orbit interaction can be utilized for direct electric-field tuning of the propagation of spin waves in a single-crystal yttrium iron garnet magnonic waveguide. Magnetoelectric coupling not due to the spin-orbit interaction and, hence, an order of magnitude weaker leads to electric-field modification of the spin-wave velocity for waveguide geometries w...

It has been established experimentally that Bi2Te3 and Bi2Se3 are topological insulators, with zero band gap surface states exhibiting linear dispersion at the Fermi energy. Standard density functional theory (DFT) methods such as PBE lead to large errors in the band gaps for such strongly correlated systems, while more accurate GW methods are too expensive computationally to apply to the thin ...

By the end of the 20th century, the research of electromagnetic behavior of π-electrons in organic crystals made several outstanding achievements. Since 50’s, the epoch-making finding appeared every decade: enhanced conductivity in halogen complexes of aromatic hydrocarbons 1) (1954), highly conductive radical salts of a π-acceptor TCNQ 2) (1960), a charge transfer complex TTF-TCNQ with quasi-o...

Semiconductor surfaces and ultrathin interfaces exhibit an interesting variety of two-dimensional quantum matter phases, such as charge density waves, spin density waves and superconducting condensates. Yet, the electronic properties of these broken symmetry phases are extremely difficult to control due to the inherent difficulty of doping a strictly two-dimensional material without introducing...

Spin waves are the elementary excitations of the spin system in a magnetically ordered material state and magnons are their quasi particles. In the following article, we will discuss Brillouin light scattering (BLS) spectroscopy which is now a well-established tool for the characterization of spin waves. BLS is the inelastic scattering of light from spin waves and confers several benefits: the ...