Giant spin polarization and a pair of antiparallel spins in a chiral superconductor.

Chiral molecules can exhibit spin-selective charge emission, which is known as chirality-induced spin selectivity1,2. Despite the constituent light elements of the molecules, their spin polarization can approach or even exceed that of typical ferromagnets. This powerful capability may lead to applications in the chiral spintronics2 field. Although the origin of spin selectivity is elusive, two microscopic phenomena have been suggested based on experimental results: effective enhancement of spin-orbit interactions3 and chirality represented by a pair of oppositely polarized spins4,5. However, the hypotheses remain to be verified. Here we report the simultaneous observation of these two phenomena in an organic chiral superconductor by magnetoresistance measurements in the vicinity of the superconducting transition temperature. A pair of oppositely polarized spins is demonstrated by spatially mapping the spin polarity in an electric alternating current excitation. The obtained spin polarization exceeds that of the Edelstein effect6-10 by several orders of magnitude, which indicates an effective enhancement of the spin-orbit interaction. Our results demonstrate a solid-state analogue of spin accumulations assumed for chiral molecules, and may provide clues to the origin of their molecular counterparts. In addition, the innovative capability of spin-current sourcing will invigorate superconducting spintronics research11.

Temperature distributions of electron beam-irradiated samples by scanning electron microscopy.

An electron beam (EB) generated by a scanning electron microscope (SEM) was used to irradiate two samples having different thermal conductivities, and the resulting temperatures of the EB-irradiated areas as well as the temperature distributions within the samples were then measured using a thermal camera. These measurements showed overall increases in sample temperatures, as well as revealed temperature rises at the EB-irradiated areas that had little difference with one of the theoretical predictions. Differences between the actual and the predicted temperature measurements were analysed in terms of the accuracy with which parameters could be estimated. The temperature distributions of the samples were measured and, On the basis of the results, it was hypothesized that the temperature differential over an irradiated sample will be inversely correlated with its thermal conductivity.

Site-specific evolution of surface stress during the room-temperature oxidation of the Si(111)-(7 x 7) surface.

The reaction of molecular oxygen with the Si(111)-7 x 7 surface is investigated at room temperature using in situ scanning tunneling microscopy and surface stress measurements to reveal the quantitative relationship between site-specific oxygen coverage and a decrease in tensile surface stress. This relationship is described using a modified form of the reaction model originally proposed by Dujardin et al. We show that the decrease in tensile surface stress is greatest for the faulted subunits of the 7 x 7 cell and determine the stress signatures of different reaction products, including the absence of long-lived metastable species with a unique stress signature.