24 research outputs found
Quantum Manifestations of Classical Stochasticity in the Mixed State
We investigate the QMCS in structure of the eigenfunctions, corresponding to
mixed type classical dynamics in smooth potential of the surface quadrupole
oscillations of a charged liquid drop. Regions of different regimes of
classical motion are strictly separated in the configuration space, allowing
direct observation of the correlations between the wave function structure and
type of the classical motion by comparison of the parts of the eigenfunction,
corresponding to different local minima.Comment: 4 pages, 3 figure
Hallmarks of tunneling dynamics with broken reflective symmetry
We study features of tunneling dynamics in an exactly-solvable model of N=4
supersymmetric quantum mechanics with a multi-well potential and with broken
reflective symmetry. Quantum systems with a phenomenological potential of this
type demonstrate the phenomenon of partial localization of under-barrier
states, possibly resulting in the appearance of the so-called "resonant"
tunneling, or the phenomenon of coherent tunneling destruction, referring to
the complete localization. Taking the partial localization and the coherent
tunneling destruction as basic examples, we indicate main advantages of using
isospectral exactly-solvable Hamiltonians in studies quantum mechanical systems
with two- and three-well potentials. They, in particular, are: having enough
freedom of changing the potential shape in a wide range, that allows one to
choose an exactly-solvable model close to characteristics of the
phenomenological one; ability of changing the number of local minima and
symmetry characteristics of the potential (symmetric or deformed) without
changing the main part of the spectrum; engaging a smart basis of states, that
dramatically decreases the dimensionality of matrices used in the
diagonalization procedure of the corresponding spectral problem.Comment: 32 pages, 10 Figs; v2: 29 pages, 10 Figs, corrected versio
A New Two-Parameter Family of Potentials with a Tunable Ground State
In a previous paper we solved a countably infinite family of one-dimensional
Schr\"odinger equations by showing that they were supersymmetric partner
potentials of the standard quantum harmonic oscillator. In this work we extend
these results to find the complete set of real partner potentials of the
harmonic oscillator, showing that these depend upon two continuous parameters.
Their spectra are identical to that of the harmonic oscillator, except that the
ground state energy becomes a tunable parameter. We finally use these
potentials to analyse the physical problem of Bose-Einstein condensation in an
atomic gas trapped in a dimple potential.Comment: 15 pages, 5 figure