https://www.selleckchem.com/products/iox2.html Realizing strong photon-photon interactions in a solid-state setting is a major goal with far reaching potential for optoelectronic applications. Using Landau's quasiparticle framework combined with a microscopic many-body theory, we explore the interactions between exciton-polaritons and trions in a two-dimensional semiconductor injected with an electron gas inside a microcavity. We show that particle-hole excitations in the electron gas mediate an attractive interaction between the polaritons, whereas the interaction between trions and polaritons mediated by the exchange of an electron can be either repulsive or attractive. These mediated interactions are intrinsic to the quasiparticles and are also present in the absence of light. Importantly, they can be tuned to be more than an order of magnitude stronger than the direct polariton-polariton interaction in the absence of the electron gas, thereby providing a promising outlook for nonlinear optical components. Finally, we compare our theoretical predictions to two recent experiments.Spin-current generation by electrical means is among the core phenomena driving the field of spintronics. Using ab initio calculations we show that a room-temperature metallic collinear antiferromagnet RuO_2 allows for highly efficient spin-current generation, arising from anisotropically spin-split bands with conserved up and down spins along the Néel vector axis. The zero net moment antiferromagnet acts as an electrical spin splitter with a 34° propagation angle between spin-up and spin-down currents. The corresponding spin conductivity is a factor of 3 larger than the record value from a survey of 20 000 nonmagnetic spin-Hall materials. We propose a versatile spin-splitter-torque concept circumventing limitations of spin-transfer and spin-orbit torques in present magnetic memory devices.In quantum systems, a subspace spanned by degenerate eigenvectors of the Hamiltonian may have higher