842 research outputs found
Improved Magnetic Information Storage using Return-Point Memory
The traditional magnetic storage mechanisms (both analog and digital) apply
an external field signal H(t) to a hysteretic magnetic material, and read the
remanent magnetization M(t), which is (roughly) proportional to H(t). We
propose a new analog method of recovering the signal from the magnetic
material, making use of the shape of the hysteresis loop M(H). The field H,
``stored'' in a region with N domains or particles, can be recovered with
fluctuations of order 1/N using the new method - much superior to the 1/sqrt{N}
fluctuations in traditional analog storage.Comment: 9 pages, 15 figure
Continuum mesoscale theory inspired by plasticity
We present a simple mesoscale field theory inspired by rate-independent
plasticity that reflects the symmetry of the deformation process. We
parameterize the plastic deformation by a scalar field which evolves with
loading. The evolution equation for that field has the form of a
Hamilton-Jacobi equation which gives rise to cusp-singularity formation. These
cusps introduce irreversibilities analogous to those seen in plastic
deformation of real materials: we observe a yield stress, work hardening,
reversibility under unloading, and cell boundary formation.Comment: 7 pages, 5 .eps figures. submitted to Europhysics Letter
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