407 research outputs found
Optical memory based on ultrafast wavelength switching in a bistable microlaser
We propose an optical memory cell based on ultrafast wavelength switching in
coupled-cavity microlasers, featuring bistability between modes separated by
several nanometers. A numerical implementation is demonstrated by simulating a
two-dimensional photonic crystal microlaser. Switching times of less than 10
ps, switching energy around 15--30 fJ and on-off contrast of more than 40 dB
are achieved. Theoretical guidelines for optimizing the performance of the
memory cell in terms of switching time and energy are drawn.Comment: to appear in Optics Letter
Graphene under the influence of Aharonov-Bohm flux and constant magnetic field
Investigation of real two-dimensional systems with Dirac-like electronic
behavior under the influence of magnetic field is challenging and leads to many
interesting physical results. In this paper we study 2D graphene model with a
particular form of magnetic field as a superposition of a homogeneous field and
an Aharonov-Bohm vortex. For this configuration, electronic wave functions and
energy spectrum were obtained and it was shown that the magnetic Aharonov-Bohm
vortex plays the role of a charge impurity. As a demonstration of vacuum
properties of the system, vacuum current, as well as an electric current, is
calculated and their representation for particular limiting cases of magnetic
field is obtained
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