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We report on new results of a search for two-photon interaction with axionlike particles (ALPs). The experiment was carried out at a synchrotron radiation facility using a "light shining through a wall (LSW)" technique. For this purpose, we have developed a novel pulsed-magnet system, composed of multiple racetrack-magnets and a transportable power supply. It produces fields of about 10 T over 0.8 m with a high repetition rate of 0.2 Hz and yields a new method of probing vacuum with high intensity fields. The data obtained with a total of 27,676 pulses provide a limit on the ALP-two-photon coupling constant that is more stringent by a factor of 5.2 compared to a previous x-ray LSW limit for the ALP mass below 0.1 eV., Comment: 5 pages, 4 figures, 1 table

A theoretical investigation reveals that the photon drag effect (PDE) is induced in a grating slab with deformation by the Berry curvature in phase space. It drifts the momentum of light, and gives asymmetric PDE signals in momentum space. Large PDE signals are observed even near the $\mathrm{\ensuremath{\Gamma}}$ point. This characteristic agrees well with our theoretical results.

We report direct observation of magnetochiral (MCh) effects for the $X$-band microwaves through a single metamolecule consisting of a copper chiral structure and ferrite rod. A fictitious interaction between chirality and magnetism is realized in the metamolecule without intrinsic electronic interactions. The MCh effects are induced at the resonant optical activities by applying a weak dc magnetic field of 1 mT, and are increased with the magnetic field. The nonreciprocal differences in refractive indices are evaluated to be ${10}^{\ensuremath{-}3}$ at 200 mT.

We study a new aspect of the Berry-phase effect as the collaborative x-ray translation by a crystal with undulated deformation. The macroscopic translation was observed around the interface of a heteroepitaxial crystal deformed by quantum dots of $4.1$ germanium monolayers on a silicon substrate. The quantum dots formed a large local gradient of deformation at the interface, which triggered the x-ray translation into two directions. This effect provides a new probe for investigating the interfacial strain, and leads to a single-crystal beam splitter with parallel exit beams.

We experimentally demonstrated an enhanced translation of an x-ray beam nearly parallel to the diffracting planes over millimeter distances in a deformed silicon crystal. This effect is a consequence of the Berry-phase effect in phase space [K. Sawada et al., Phys. Rev. Lett. 96, 154802 (2006)], which enables an interplay between the gap in the dispersion surface in momentum space and the atomic displacements in real space. Such an interplay in phase space enhances the beam translation by some 5 orders of magnitude, leading to the macroscopic effect.

X-ray nonlinear optics, which has been considered as a scientific frontier to be explored with x-ray free-electron lasers, is accessible with existing synchrotron x-ray sources, revealing its unique features. We demonstrate that x-ray parametric down-conversion is observed indirectly through quantum mechanical interference known as the Fano effect. By introducing a novel concept of photonic discrete levels, we determine the second order nonlinear susceptibility of diamond, and find a strong resonance enhancement at the core absorption edge that presents firm experimental evidence to develop x-ray nonlinear optics.

We develop a theory for the trajectory of an x ray in the presence of a crystal deformation. A set of equations of motion for an x-ray wave packet including the dynamical diffraction is derived, taking into account the Berry phase as a correction to geometrical optics. The trajectory of the wave packet has a shift of the center position due to a crystal deformation. Remarkably, in the vicinity of the Bragg condition, the shift is enhanced by a factor $\omega /\Delta \omega$ ($\omega$: frequency of an x ray, $\Delta\omega$: gap frequency induced by the Bragg reflection). Comparison with the conventional dynamical diffraction theory is also made., Comment: 4 pages, 2 figures. Title changed

We theoretically propose that the optical analog of a Lorentz force acting on a ray of light is realized in multiferroic materials such as GaFeO$_3$ showing the magnetoelectric effect. The toroidal moment plays the role of a ``vector potential" while its rotation corresponds to a "magnetic field" for photons. Hence, the light is subject to the Lorentz force when propagating through the domain wall region of the ferromagnetic or ferroelectric order. A realistic estimate on the magnitude of this effect is given., Comment: 4 pages, 2 figures. The title is changed