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Search Results: 1 - 10 of 43 matches for " Miztli Yepez "
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Wave Transport in One-Dimensional Disordered Systems with Finite-Size Scatterers
Marlos Diaz,Pier A. Mello,Miztli Yepez,Steven Tomsovic
Physics , 2014, DOI: 10.1103/PhysRevB.91.184203
Abstract: We study the problem of wave transport in a one-dimensional disordered system, where the scatterers of the chain are $n$ barriers and wells with statistically independent intensities and with a spatial extension $\l_c$ which may contain an arbitrary number $\delta/2\pi$ of wavelengths, where $\delta = k l_c$. We analyze the average Landauer resistance and transmission coefficient of the chain as a function of $n$ and the phase parameter $\delta$. For weak scatterers, we find: i) a regime, to be called I, associated with an exponential behavior of the resistance with $n$, ii) a regime, to be called II, for $\delta$ in the vicinity of $\pi$, where the system is almost transparent and less localized, and iii) right in the middle of regime II, for $\delta$ very close to $\pi$, the formation of a band gap, which becomes ever more conspicuous as $n$ increases. In regime II, both the average Landauer resistance and the transmission coefficient show an oscillatory behavior with $n$ and $\delta$. These characteristics of the system are found analytically, some of them exactly and some others approximately. The agreement between theory and simulations is excellent, which suggests a strong motivation for the experimental study of these systems. We also present a qualitative discussion of the results.
Superfluid turbulence from quantum Kelvin wave to classical Kolmogorov cascades
Jeffrey Yepez
Physics , 2009, DOI: 10.1103/PhysRevLett.103.084501
Abstract: A novel unitary quantum lattice gas algorithm is used to simulate quantum turbulence of a BEC described by the Gross-Pitaevskii equation on grids up to 5760^3. For the first time, an accurate power law scaling for the quantum Kelvin wave cascade is determined: k^{-3}. The incompressible kinetic energy spectrum exhibits very distinct power law spectra in 3 ranges of k-space: a classical Kolmogorov k^{-5/3} spectrum at scales much greater than the individual quantum vortex cores, and a quantum Kelvin wave cascade spectrum k^{-3} on scales of order the vortex cores. In the semiclassical regime between these two spectra there is a pronounced steeper spectral decay, with non-universal exponent. The Kelvin k^{-3} spectrum is very robust, even on small grids, while the Kolmogorov k^{-5/3} spectrum becomes more and more apparent as the grids increase from 2048^3 grids to 5760^3.
k^-3 superfluid spectrum of highly curved interacting quantum vortices
Jeffrey Yepez
Physics , 2010,
Abstract: Presented is a prediction, based on the Frenet-Serret differential geometry of space curves, that the wave number dependence of the average kinetic energy per unit length of two mutually interacting highly curved quantum vortex scales as k^-3. The interacting quantum vortices are helical in shape, supporting circularly polarized counter-propagating waves, with arbitrary curvature and torsion. This power-law spectrum agrees with the high-k spectrum found in precise quantum simulations of turbulent superfluidity with tangle of highly curved and excited quantum vortices.
Quantum logic as superbraids of entangled qubit world lines
Jeffrey Yepez
Physics , 2009, DOI: 10.1103/PhysRevA.81.022328
Abstract: Presented is a topological representation of quantum logic that views entangled qubit spacetime histories (or qubit world lines) as a generalized braid, referred to as a superbraid. The crossing of world lines is purely quantum in nature, most conveniently expressed analytically with ladder-operator-based quantum gates. At a crossing, independent world lines can become entangled. Complicated superbraids are systematically reduced by recursively applying novel quantum skein relations. If the superbraid is closed (e.g. representing quantum circuits with closed-loop feedback, quantum lattice gas algorithms, loop or vacuum diagrams in quantum field theory), then one can decompose the resulting superlink into an entangled superposition of classical links. In turn, for each member link, one can compute a link invariant, e.g. the Jones polynomial. Thus, a superlink possesses a unique link invariant expressed as an entangled superposition of classical link invariants.
String model of the Hydrogen Atom
Omar Yepez
Physics , 2007,
Abstract: A non-moving electron hydrogen model is proposed, resolving a long standing contradiction (94 years) in the hydrogen atom. This, however, forces to not use the "in an orbit point particle kinetic energy" as the phenomenon responsible for the atom stability. The repulsion between the masses of the electron and proton is what is responsible of such stability. The mass of the electron is a field fully described by the uncertainty principle through the confinement of the particle, which is also consistent with the general theory of relativity that states: "mass-energy tells the space how to bend". Ergo, mass exerts a tension on its surrounding space and the lighter the mass the larger the space it will occupy. Based on this concept it is proposed that the orbital is the electron. The electron's orbitals are just the electron's different ways of intersecting the space; with different magnetic momenta. The coupling of this momenta with the magnetic moment of the proton finally explains the hyperfine structure of the hydrogen spectrum with an overwhelming simplicity
The Flat Deuteron
Omar Yepez
Physics , 2005,
Abstract: The new model was applied to the femtometer toroidal structures found for the deuteron. It was possible to relate the magnetic moment and the energy of the particle to the torus geometric parameters. Excellent agreement between the magnetic moment of the deuteron and the theory developed for a time consuming intersecting 3D torus in a 2D space was found. It was possible to discriminate between which structures present a magnetic moment and which one would produce an anapole moment. This supports the concept that there are orientations of the torus that make it lose its magnetic moment, which is the key to understanding the EPR paradox. The mass energy of the particle changed with each structure, but the mass density was constant, which is consistent with the tension exerted on the space as the source of the particle's "mass" or more appropriately said the particle's density.
A Lattice-Gas with Long-Range Interactions Coupled to a Heat Bath
Jeffrey Yepez
Physics , 1994,
Abstract: Introduced is a lattice-gas with long-range 2-body interactions. An effective inter-particle force is mediated by momentum exchanges. There exists the possibility of having both attractive and repulsive interactions using finite impact parameter collisions. There also exists an interesting possibility of coupling these long-range interactions to a heat bath. A fixed temperature heat bath induces a permanent net attractive interparticle potential, but at the expense of reversibility. Thus the long-range dynamics is a kind of a Monte Carlo Kawasaki updating scheme. The model has a $P\rho T$ equation of state. Presented are analytical and numerical results for the a lattice-gas fluid governed by a nonideal equation of state. The model's complexity is not much beyond that of the FHP lattice-gas. It is suitable for massively parallel processing and may be used to study critical phenomena in large systems.
Einstein's vierbein field theory of curved space
Jeffrey Yepez
Physics , 2011,
Abstract: General Relativity theory is reviewed following the vierbein field theory approach proposed in 1928 by Einstein. It is based on the vierbein field taken as the "square root" of the metric tensor field. Einstein's vierbein theory is a gauge field theory for gravity; the vierbein field playing the role of a gauge field but not exactly like the vector potential field does in Yang-Mills theory--the correction to the derivative (the covariant derivative) is not proportional to the vierbein field as it would be if gravity were strictly a Yang-Mills theory. Einstein discovered the spin connection in terms of the vierbein fields to take the place of the conventional affine connection. To date, one of the most important applications of the vierbein representation is for the derivation of the correction to a 4-spinor quantum field transported in curved space, yielding the correct form of the covariant derivative. Thus, the vierbein field theory is the most natural way to represent a relativistic quantum field theory in curved space. Using the vierbein field theory, presented is a derivation of the the Einstein equation and then the Dirac equation in curved space. Einstein's original 1928 manuscripts translated into English are included.
Highly covariant quantum lattice gas model of the Dirac equation
Jeffrey Yepez
Physics , 2011,
Abstract: We revisit the quantum lattice gas model of a spinor quantum field theory-the smallest scale particle dynamics is partitioned into unitary collide and stream operations. The construction is covariant (on all scales down to a small length {\ell} and small time {\tau} = c {\ell}) with respect to Lorentz transformations. The mass m and momentum p of the modeled Dirac particle depend on {\ell} according to newfound relations m = mo cos (2{\pi}{\ell}/{\lambda}) and p = (h/2{\pi}{\ell}) sin(2{\pi}{\ell}/{\lambda}), respectively, where {\lambda} is the Compton wavelength of the modeled particle. These relations represent departures from a relativistically invariant mass and the de Broglie relation-when taken as quantifying numerical errors the model is physically accurate when {\ell} {\ll} {\lambda}. Calculating the vacuum energy in the special case of a massless spinor field, we find that it vanishes (or can have a small positive value) for a sufficiently large wave number cutoff. This is a marked departure from the usual behavior of such a massless field.
Wave Transport in disordered waveguides: closed channel contributions and the coherent and diffuse fields
M. Yepez
Physics , 2014, DOI: 10.1063/1.4862414
Abstract: We study the wave transport through a disordered system inside a waveguide. The expectation value of the complex reflection and transmission coefficients (the coherent fields) as well as the transmittance and reflectance are obtained numerically. The numerical results show that the averages of the coherent fields are only relevant for direct processes, while the transmittance and reflectance are mainly dominated by the diffuse intensities, which come from the statistical fluctuations of the fields.
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