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The recording and retrieval of signals below 100 nm mark length were attempted with elliptical bubble-type super-resolution technology with platinum oxide (PtOx) and ductile AgInSbTe layers, using the same optical system as that of a digital versatile disk (a 635 nm wavelength red laser system). The carrier-to-noise ratio (CNR) of over 47 dB for 100 nm mark length signals (over 43 dB for 80 nm mark length signals) was obtained, which can be considered as a commercially acceptable level of CNR. The recording mechanism of the sample disk was shown through the transmission electron microscopy cross-section image observation to be by rigid elliptical bubble formation at the PtOx layer located between the AgInSbTe layers. The results of this report represent the potential for a much higher-density storage using the red laser system and a subterabyte optical storage using the blue laser system.

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We discuss the conditions for a non-vanishing Dirac phase δ and mixing angle θ 13 , sources of CP violation in neutrino oscillations, to be uniquely responsible for the observed matter-antimatter asymmetry of the Universe through leptogenesis. We show that this scenario, that we call δ-leptogenesis, is viable when the degenerate limit for the heavy right-handed (RH) neutrino spectrum is considered. We derive an interesting joint condition on sin θ 13 and the absolute neutrino mass scale that can be tested in future neutrino oscillation experiments. In the limit of the hierarchical heavy RH neutrino spectrum, we strengthen the previous result that δ-leptogenesis is only very marginally allowed, even when the production from the two heavier RH neutrinos is taken into account. An improved experimental upper bound on sin θ 13 and/or an account of quantum kinetic effects could completely rule out this option in the future. Therefore, δ-leptogenesis can be also regarded as motivation for models with degenerate heavy neutrino spectrum. Viability of Dirac phase leptogenesisJournal of Cosmology and Astroparticle Physics 04 (2008) 033 (stacks.iop.org/JCAP/2008/i=04/a=033) 3 More exactly, in [7], 4 × 10 8 GeV was found. Here we are using a slightly higher value that is obtained, as we will see, when the reduced experimental error on the baryon asymmetry and on the atmospheric neutrino mass scale is taken into account. 4 Flavor effects were first considered in [12] and then in [13] in the particular case of two RH neutrinos. However, in these papers, it was found that flavor effects can change the final asymmetry only of O(1) factors compared to the unflavored case. The possibility for a large enhancement was first found in [14] in the case of resonant leptogenesis and more generally in [15]-[17]. Here, in particular, there was also first discussed the potential role of low-energy phases in providing an additional CP violating contribution to the flavored CP asymmetries.Journal of Cosmology and Astroparticle Physics 04 (2008) 033 (stacks.iop.org/JCAP/2008/i=04/a=033)

We have previously proposed a piezoelectric sensor configuration determined using an optical-access method and reported the simulation results. Two issues have to be resolved for fabricating such a sensor; one is to develop a suitable optical-to-electrical conversion technique, and the other is to develop an optical measurement method for piezoelectric resonance. We examined the use of a Schottky-barrier photodiode (SBPD) for photoelectric conversion to excite piezoelectric vibration in the very high frequency (VHF) region. We found that the photoelectric output of SBPD corresponds to the intensity of the modulated light. The excitation power of piezoelectric vibration is between 10 µW (at 70 MHz) and 32 µW (at 50 MHz). However, optical detection of piezoelectric vibration is difficult. In this paper, we propose a waveguide-type light circuit using a pair of Y-branch elements based on the Mach-Zender interferometer. An analysis on the sensitivity of the circuit for vibration detection was carried out and relatively higher sensitivity was predicted. Furthermore, the photoelastic constant p 66 for AT-cut quartz was measured.