Ken-ichi Uchida

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Energy harvesting technologies, which generate electricity from environmental energy, have been attracting great interest because of their potential to power ubiquitously deployed sensor networks and mobile electronics. Of these technologies, thermoelectric (TE) conversion is a particularly promising candidate, because it can directly generate electricity(More)
The spin Seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. The inverse spin Hall effect converts the injected spin current into a transverse(More)
We present 15 – 20 μm long-slit spectra, from the Infrared Spectrograph (IRS) on Spitzer, of NGC 7023. We observe recently-discovered interstellar emission features, at 15.9, 16.4, 17.0, 17.4, 17.8, and 18.9 μm, throughout the reflection nebula. The 16.4 μm emission feature peaks near the photodissociation front northwest of the star, as do the aromatic(More)
Surface plasmons, free-electron collective oscillations in metallic nanostructures, provide abundant routes to manipulate light-electron interactions that can localize light energy and alter electromagnetic field distributions at subwavelength scales. The research field of plasmonics thus integrates nano-photonics with electronics. In contrast, electronics(More)
We present the first Spitzer Infrared Spectrograph observations of the disks around classical T Tauri stars: spectra in the 5.2-30 μm range of six stars. The spectra are dominated by emission features from amorphous silicate dust, and a continuous component from 5 to 8 μm that in most cases comprises an excess above the photosphere throughout our spectral(More)
Asuka Miura,1 Takashi Kikkawa,2,3 Ryo Iguchi,2 Ken-ichi Uchida,2,4,5,6,* Eiji Saitoh,2,3,6,7 and Junichiro Shiomi1,8,* 1Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan 2Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan 3WPI Advanced Institute for Materials Research, Tohoku University, Sendai(More)
Applying magnetic fields has been the method of choice to magnetize non-magnetic materials, but they are difficult to focus. The magneto-electric effect and voltage-induced magnetization generate magnetization by applied electric fields, but only in special compounds or heterostructures. Here we demonstrate that a simple metal such as gold can be magnetized(More)
The Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope (SST) has been used to obtain low and moderate resolution spectra of the dust and gas-rich quasar APM 08279+5255 (z=3.91). Broad Paschen α and β recombination lines of hydrogen were detected at wavelengths of 9.235 and 6.315μm, as well as a strong, red continuum that is a smooth power law(More)