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A peak field of 1200 T was generated by the electromagnetic flux-compression (EMFC) technique with a newly developed megagauss generator system. Magnetic fields closely up to the turn-around peak were recorded by a reflection-type Faraday rotation magnetic-field optical-fiber probe. The performance was analyzed and compared with data obtained by the preceding EMFC experiments to show a significant increase in the liner imploding speed of up to 5 km/s.

Magnetization measurements of LaCoO 3 have been carried out up to 133 T generated with a destructive pulse magnet at a wide temperature range from 2 to 120 K. A novel magnetic transition was found at B > 100 T and T > T * = 32 ± 5 K which is characterized by its transition field increasing with increasing temperature. At T < T * , the previously reported transition at B ∼ 65 T was observed. Based on the obtained B-T phase diagram and the Clausius-Clapeyron relation, the entropy of the high-field phase at 80 K is found to be smaller for about 1.5 J K −1 mol −1 than that of the low-field phase. We suggest that the observed two high-field phases may originate in different spatial orders of the spin states and possibly other degrees of freedom such as orbitals. An inherent strong correlation of spin states among cobalt sites should have triggered the emergence of the ordered phases in LaCoO 3 at high magnetic fields. PACS numbers: 75.30.Wx, 75.25.Dk, 75.47.Lx, 75.30.Cr Due to the strong correlations between the electrons, the transition metal oxide serves as a vast field hosting rich electronic phases represented by high-temperature superconductivity, colossal magnetoresistance and magnetic-field-induced ferroelectorics [1,2]. Among them, cobalt oxides are unique for their spin state degrees of freedom which not only bring about a magnetic crossover but also a metal-insulator transition (MIT) [3] in the thermal evolution. Perovskite cobalt oxide, LaCoO 3 , has attracted significant attention for more than five decades for its unusual magnetic and transport properties, namely, the crossover from a diamagnet to a Curie paramagnet at 100 K and the transition from a paramagnetic insulator to a paramagnetic metal at 500 K with increasing temperature [4]. Within the ionic picture, possible spin states of Co g , S = 1) is also argued to be stabilized due to the strong hybridization with the O 2p state [5]. Representative ideas describing the spin states of LaCoO 3 in the temperature range above 100 K are (i) the LS-HS mixture state [6][7][8][9][10][11] and (ii) the IS state [5,12,13]. However, they are still controversial. It is notable that recent theoretical studies on the two-orbital Hubbard model have qualitatively reproduced the thermally induced spin crossover and MIT with paramagnetic local moments [14][15][16]. On the other hand, they are inclined to predict the ordering of different spin states which is not found experimentally except for a few studies [17].The validity of the models on spin states should be well judged by their field effects. One can uncover magnetic excited states using high magnetic fields at low temperatures, eliminating the thermal effect. Thermodynamical properties of the magnetic phase can also be revealed by observing its temperature and magnetic field dependence [18,19] and possibly the orbitals are spatially ordered [22,23] and further, the following two magnetization jumps at B > 100 T are predicted by the Ising type SSC model [22]. With the explosive magnetic flux compression techni...

We experimentally demonstrate one-way transparency of light in multiferroic CuB(2)O(4). The material is rendered transparent for light propagating in one direction, while opaque for light propagating in the opposite direction. The novel transparency results from a destructive interference of the electric dipole and magnetic dipole transitions. The realization of the effect has been accomplished by the application of a high magnetic field and the proper selection of the propagation direction of light in agreement with our quantum mechanical formulation of nonreciprocal directional dichroism.

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