Browsing by Author "Theodorakis, Stavros"
Now showing items 21-40 of 43
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Magnetic-field inversion in vortices in multilayers
Theodorakis, Stavros; Leontidis, Epameinondas (1997)We present a description of very dense vortex lattices in highly anisotropic multilayers, for high fields parallel to the layers. We show that a magnetic-field inversion can occur away from the center of a vortex, provided ...
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Magnetic-field inversion in vortices in multilayersAAA
Theodorakis, Stavros; Leontidis, Epameinondas (1997)We present a description of very dense vortex lattices in highly anisotropic multilayers, for high fields parallel to the layers. We show that a magnetic-field inversion can occur away from the center of a vortex, provided ...
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Model for layered superconductors: From Josephson coupling to three-dimensional behavior
Feinberg, D.; Theodorakis, Stavros; Ettouhami, A. M. (1994)We present a model for layered superconductors, where the order parameter between the layers is nonzero, due to proximity effects. In the limit of decoupled layers, this model gives all the terms of the usual Lawrence-Doniach ...
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The motto in Edgar Allan Poe's "The purloined letter"
Theodorakis, Stavros (2009)
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A new kinetic term in the phenomenology of layered superconductors
Theodorakis, Stavros (1993)We show that the Lawrence-Doniach free energy for layered superconductors can be derived from an anisotropic Ginzburg-Landau free energy with a spatially dependent coefficient for the quadratic term. Our derivation indicates ...
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Oscillations of a Bose-Einstein condensate in a rapidly contracting circular box
Theodorakis, Stavros; Psaroudaki, C. (2009)A Bose-Einstein condensate will evolve almost adiabatically if the number of atoms is large enough, even though the trap parameters may be changing rapidly. We demonstrate this by examining a Bose-Einstein condensate in a ...
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Oscillations of a candle burning at both ends
Theodorakis, Stavros; Paridi, K. (2009)A candle burning at both ends will oscillate vertically about the horizontal, forming the popular "candle see-saw" or "stearic motor." The reason for these oscillations is that at any particular instant, more drops of ...
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The paradox of the floating candle that continues to burn
Theodorakis, Stavros; Aristidou, C. (2012)What happens after lighting a paraffin candle that is barely floating in water and kept upright with the aid of an appropriately weighted nail attached to its bottom? Presumably, it should sink because the buoyant force ...
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A phenomenological model for high Tc superconductors
Theodorakis, Stavros (1988)We propose a phenomenological model describing the high Tc superconductors. Adjacent Cu-O layers have negative Josephson couplings, forcing the order paramater to change sign from one layer to the next. The number of closely ...
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Phenomenological model for organic superconductors
Theodorakis, Stavros (1998)We present a Ginzburg-Landau model that explains some recently observed features in the upper critical field of the organic superconductor (TMTSF)2PF6. This model takes into account the finite size of the superconducting ...
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Piecewise analytic approximation for Bose-Einstein condensates in isotropic harmonic traps
Theodorakis, Stavros (2004)Analytic simulacra of the wave functions in the regions around the origin and far from the origin were constructed to emulate the ground state and the single-vortex state of a Bose-Einstein condensate in an isotropic ...
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Piecewise linear emulation of propagating fronts as a method for determining their speeds
Theodorakis, Stavros; Svoukis, E. (2003)The selected speed of pushed fronts was found through analytic calculations. The resulting analytic solution constitutes an excellent approximation to the exact propagating front, yielding also the correct value for the ...
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Piecewise linear emulator of the nonlinear Schrödinger equation and the resulting analytic solutions for Bose-Einstein condensates
Theodorakis, Stavros (2003)A most general method for finding very good analytic approximate solutions to the cubic nonlinear Schrodinger equation is presented. This method applies whenever the nonlinearity in that equation is a purely cubic one. It ...
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Positive curvature of Hc2 in layered superconductors
Theodorakis, Stavros; Teanović, Z. (1989)We present a phenomenological calculation of the equilibrium upper critical field Hc2 in layered superconductors. We find that Hc2(T) has positive curvature near Tc, but becomes linear further away, as a result of a proximity ...
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Proximity effect through higher derivatives in superconducting filaments
Theodorakis, Stavros (1999)We show that extremely thin superconducting filaments placed in the midst of insulating material do maintain their superconducting state, but only if higher derivative terms are included in the free energy. It is these ...
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Quark mass hierarchies and natural flavor conservation as stable fixed points
Axenides, Minos; Theodorakis, Stavros (1988)In the context of two-Higgs models, a hierarchy of heavy quark masses can be generated naturally at the infrared fixed point of the renormalization group equations for the Yukawa couplings, while flavor-changing neutral ...
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Speed selection mechanism for propagating fronts in reaction-diffusion systems with multiple fields
Theodorakis, Stavros; Leontidis, Epameinondas (2002)We introduce a speed selection mechanism for front propagation in reaction-diffusion systems with multiple fields. This mechanism applies to pulled and pushed fronts alike, and operates by restricting the fields to large ...
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Speed selection mechanism for propagating fronts in reaction-diffusion systems with multiple fields
Theodorakis, Stavros; Leontidis, Epameinondas (2002)We introduce a speed selection mechanism for front propagation in reaction-diffusion systems with multiple fields. This mechanism applies to pulled and pushed fronts alike, and operates by restricting the fields to large ...
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Article
Speed selection mechanism for propagating fronts in reaction-diffusion systems with multiple fields123
Theodorakis, Stavros; Leontidis, Epameinondas (2002)We introduce a speed selection mechanism for front propagation in reaction-diffusion systems with multiple fields. This mechanism applies to pulled and pushed fronts alike, and operates by restricting the fields to large ...
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Spontaneous magnetic moment of flowing superfluid 3He-B in electric fields
Theodorakis, Stavros (1988)An electric field creates a spontaneous magnetic moment in flowing superfluid 3He-B, if the direction of flow is perpendicular to the electric field. This magnetic moment can be detected experimentally with ease, by reversing ...