L. Kaplan
Tulane University
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Featured researches published by L. Kaplan.
Nonlinearity | 1999
L. Kaplan
We review recent progress in attaining a quantitative understanding of the scarring phenomenon, the non-random behavior of quantum wavefunctions near unstable periodic orbits of a classically chaotic system. The wavepacket dynamics framework leads to predictions about statistical long-time and stationary properties of quantum systems with chaotic classical analogues. Many long-time quantum properties can be quantitatively understood using only short-time classical dynamics information; these include wavefunction intensity distributions, intensity correlations in phase space and correlations between wavefunctions, and distributions of decay rates and conductance peaks in weakly open systems. Strong deviations from random matrix theory are predicted and observed in the presence of short unstable periodic orbits.We review recent progress in attaining a quantitative understanding of the scarring phenomenon, the non-random behaviour of quantum wavefunctions near unstable periodic orbits of a classically chaotic system. The wavepacket dynamics framework leads to predictions about statistical long-time and stationary properties of quantum systems with chaotic classical analogues. Many long-time quantum properties can be quantitatively understood using only short-time classical dynamics information; these include wavefunction intensity distributions, intensity correlations in phase space and correlations between wavefunctions, and distributions of decay rates and conductance peaks in weakly open systems. Strong deviations from random matrix theory are predicted and observed in the presence of short unstable periodic orbits.
Physical Review A | 1997
L. Kaplan; Neepa T. Maitra; Eric J. Heller
We consider quantum mechanics on constrained surfaces which have non-Euclidean metrics and variable Gaussian curvature. The old controversy about the ambiguities involving terms in the Hamiltonian of order
Physical Review B | 2009
Giuseppe Celardo; L. Kaplan
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Physical Review A | 2009
Tae-Woo Lee; Sean D. Huver; Hwang Lee; L. Kaplan; Steven B. McCracken; Changjun Min; Dmitry Uskov; Christoph F. Wildfeuer; Georgios Veronis; Jonathan P. Dowling
multiplying the Gaussian curvature is addressed. We set out to clarify the matter by considering constraints to be the limits of large restoring forces as the constraint coordinates deviate from their constrained values. We find additional ambiguous terms of order
Physical Review D | 1995
Howard Georgi; L. Kaplan; David Morin; Andreas D. Schenk
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Physical Review D | 1994
Christopher D. Carone; Howard Georgi; L. Kaplan; David Morin
involving freedom in the constraining potentials, demonstrating that the classical constrained Hamiltonian or Lagrangian cannot uniquely specify the quantization: the ambiguity of directly quantizing a constrained system is inherently unresolvable. However, there is never any problem with a physical quantum system, which cannot have infinite constraint forces and always fluctuates around the mean constraint values. The issue is addressed from the perspectives of adiabatic approximations in quantum mechanics and Feynman path integrals, and semiclassically in terms of adiabatic actions.
Physical Review B | 2002
T. Papenbrock; L. Kaplan; G. F. Bertsch
Using an energy-independent non-Hermitian Hamiltonian approach to open systems, we fully describe transport through a sequence of potential barriers as external barriers are varied. Analyzing the complex eigenvalues of the non-Hermitian Hamiltonian model, a transition to a superradiant regime is shown to occur. Transport properties undergo a strong change at the superradiance transition, where the transmission is maximized and a drastic change in the structure of resonances is demonstrated. Finally, we analyze the effect of the superradiance transition in the Anderson localized regime.
Physical Review C | 2000
L. Kaplan; T. Papenbrock; Calvin W. Johnson
We optimize two-mode entangled number states of light in the presence of loss in order to maximize the extraction of the available phase information in an interferometer. Our approach optimizes over the entire available input Hilbert space with no constraints, other than fixed total initial photon number. We optimize to maximize the Fisher information, which is equivalent to minimizing the phase uncertainty. We find that in the limit of zero loss, the optimal state is the maximally path-entangled so-called N00N state, for small loss, the optimal state gradually deviates from the N00N state, and in the limit of large loss, the optimal state converges to a generalized two-mode coherent state, with a finite total number of photons. The results provide a general protocol for optimizing the performance of a quantum optical interferometer in the presence of photon loss, with applications to quantum imaging, metrology, sensing, and information processing.
Physical Review Letters | 2000
L. Kaplan; T. Papenbrock
We investigate the effects of top quark compositeness on various physical parameters, and obtain lower limits on the compositeness scale from electroweak precision data. We consider corrections to top quark decay rates and other physical processes. Our results depend sensitively on whether the left-handed top quark is composite. A considerable enhancement of [ital t[bar t]] production is possible if only the right-handed top quark is composite.
Physical Review A | 2009
Dmitry Uskov; L. Kaplan; A. Matthew Smith; Sean D. Huver; Jonathan P. Dowling
We study nonleptonic decays of the orbitally excited, SU(6) 70-plet baryons in order to test the hypothesis that the successes of the nonrelativistic quark model have a natural explanation in the large-Nc limit of