Spin Hall effects are commonly used as a means for interconversion between charge- and spin-currents. As an alternative mechanism for this interconversion, the Rashba-type spin splitting at the interface or the spin-momentum locking at the Dirac surface state of a topological insulator have recently been used for highly efficient spin to charge conversion. In this article, we review recent progress of the research on the above-mentioned topics and give future prospects.

In this article, we present the simultaneous SERS and electric measurement for single 1,4-benzenedithiol (BDT) molecule wired between two Au electrodes. The electrical studies reveal the existence of three meta-stable states with individual conductivity arising from different molecular adsorption sites. Each three adsorption sites of the BDT molecule has three different conductivities with more than twenty times difference together. The correlated spectroscopic measurements selectively took the solo adsorption site “bridge sites” among three possible sites. This is the first report of a site-selective technique, opening the door towards the reliable integration of molecular components into a working device. Furthermore, this hybrid spectro-electrical technique has experimentally unveiled the SERS intensity on the strength of the metal-molecule interaction, showing the interdependence between the optical and electronic properties in single-molecule junctions.

Among many candidates for a quantum bit, electron spins in Si quantum dots are one of the most promising ones for its potential to scale up and its long coherence time. Its intrinsic coherence time of an electron spin in a Si quantum dot has been measured to be ～1 μs for natural Si and ～120 μs for isotopically purified Si. A universal single-qubit gate and a two-qubit logic gate have been experimentally demonstrated. The average gate fidelity of a single-qubit gate reached 99%, a threshold required for a quantum error correction. This recent progress paves the way for the realization for a quantum computer using single electron spins in Si quantum dots.

In this report, we introduce self-organized pattern formation as well as spontaneous motion out of the coupling between rheology and chemical reaction. Such coupling is observed in various situation in industrial, geophysical, and biophysical situation. We introduce two different systems, which generates passive and active aggregates. On the one hand, various pattern due to the coupling of rheology and reaction was observed under the external force, where passive aggregate were generated at the interface. On the other hand, spontaneous interfacial motion was induced, where supposedly-active aggregate was generated. The activeness was supported by the result of small angle neutron scattering observation.

Stern-Gerlach experiments, performed in the period of old-quantum theory, are among the most fruitful experiments. To fully understand the result, the quantum mechanical adiabatic theorem, i.e. adiabatic change is necessary as well as the knowledge of electron spin. As a modern application to accelerator science, O₂ sheet beam for non-destructive beam-profile monitor is presented.