Initializing process on direct overwrite method using exchange-coupled quadilayer magneto-optical film
A direct overwrite mechanism of the exchange-coupled quadri-layered film using light intensity modulation has been investigation. The initializing process in the overwrite mechanism was studied. It was found that the writing layer had two different coercivities depending on the magnetization state of its adjacent layers. The coercivity of the writing layer in the initializing process was lower than that of the single layer. Thus, the overwrite recording was achieved with good recording characteristics. How this phenomenon plays a critical role in the initializing process was clarified. It was also found that this process occurred well above room temperature. >
Magneto-Optical Recording Characteristics of TbFeCo Media by Magnetic Field Modulation Method
To determine the most suitable composition for a magnetic field modulation recording, we investigated the static and dynamic recording (optical modulation method) characteristics of a TbFeCo film relative to an external magnetic field. It was made clear that the demagnetizing field is the chief determinant of the external magnetic field intensity and that a medium with a compensation temperature between room temperature and about 100°C is suitable for magnetic field modulation recording. AC/N of 50 dB was obtained by modulating the external magnetic field at 500 kHz. An overwriting on the pre-signal was completely realized up to the frequency of 500 kHz.
The quantum particle in a box: what we can learn from classical electrodynamics
The problem of a charged particle enclosed in an infinite square potential well is analysed from the point of view of classical theory with the addition of the electromagnetic zero-point radiation field, with the aim to explore the extent to which such an analysis can contribute to enhance our understanding of the quantum behavior. First a proper treatment is made of the freely moving particle subject to the action of the radiation field, involving a frequency cutoff ωc. The jittering motion and the effective structure of the particle are sustained by the permanent action of the zero-point field. As a result, the particle interacts resonantly with the traveling field modes of frequency ωc in its proper frame of reference, which superpose to give rise to a modulated wave accompanying the particle. This is identified with the de Broglie wave, validating the choice of Compton’s frequency for ωc. For the stationary states of particles confined in the potential well, the Lorentz force produced by the accompanying field is shown to lead to discrete values for the mean speed and to an uneven probability distribution that echoes the corresponding quantum distribution. The relevance of the results obtained and the limitations of the classical approach used, are discussed in the context of present-day stochastic electrodynamics.