arXiv subjects

J. -G. Caputo

Publications and source records attributed to J. -G. Caputo.

21 records · Page 2Linked to original sources

arXiv2006

Electromagnetically induced switching of ferroelectric thin films

We analyze the interaction of an electromagnetic spike (one cycle) with a thin layer of ferroelectric medium with two equilibrium states. The model is the set of Maxwell equations coupled to the undamped Landau-Khalatnikov equation, where we do not assume slowly varying envelopes. From linear scattering theory, we show that low amplitude pulses can be completely reflected by the medium. Large amplitude pulses can switch the ferroelectric. Using numerical simulations and analysis, we study this switching for long and short pulses, estimate the switching times and provide useful information for experiments.

nlin.PS↗

arXiv2003

A simple theory for the Raman spike

The classical stimulated Raman scattering system describing resonant interaction between two electromagnetic waves and a fast relaxing medium wave is studied by introducting a systematic perturbation approach in powers of the relaxation time. We separate amplitude and phase effects for these complex fields. The analysis of the former shows the existence of a stagnation distance after which monotonous energy transfer begins from one electromagnetic wave to the other and this quantity is calculated. Concerning phase effects we give the conditions for the formation of a Raman spike from an initial fast and large phase jump in one of the waves. The spike evolution and width estimated from the reduced model agree with the results from numerical simulations of the original system.

nlin.PS↗

arXiv2000

Stability analysis of static solutions in a Josephson junction

We present all the possible solutions of a Josephson junction with bias current and magnetic field with both inline and overlap geometry, and examine their stability. We follow the bifurcation of new solutions as we increase the junction length. The analytical results, in terms of elliptic functions in the case of inline geometry, are in agreement with the numerical calculations and explain the strong hysteretic phenomena typically seen in the calculation of the maximum tunneling current. This suggests a different experimental approach based on the use, instead of the external magnetic field the modulus of the elliptic function or the related quantity the total magnetic flux to avoid hysteretic behavior and unfold the overlapping $I_{max}(H)$ curves.

cond-mat.supr-con↗