Dynamics of quasibound state formation in the driven Gaussian potential

Abstract

The quasibound states of a particle in an inverted-Gaussian potential interacting with an intense laser field are studied using complex coordinate scaling and Floquet theory. The dynamics of the driven system is different depending on whether the driving field frequency is less than or greater than the ionization frequency. As the laser field strength is increased, a new quasibound state emerges as the result of a pitchfork bifurcation in the classical phase space. Changes in the time-averaged "dressed potential" appear related to this bifurcation and provide additional confirmation of the role of the bifurcation on the emergence of a new quasibound state. The Husimi plots of the quasibound state residues reveal strong support on the periodic orbits of the bifurcation at frequencies above the ionization frequency.

Fractal scattering in a radiation field

“…A particularly fruitful system for studying fractal scattering dynamics, both classically [3][4][5] and quantum mechanically [9,10], is the negative chlorine ion Cl − in the presence of a radiation field. In Refs.…”

Finding and pinpointing exceptional points of an open quantum system

“…In the first example, this 3-point method is used to pinpoint the exact location of an EP in H + 2 . In the second example, we study a laser-driven Gaussian potential and discover an EP close to the avoided crossing which has been reported in [18]. In section 5 the first-order Taylor coefficients of the energy difference squared are expressed in terms of expectation values.…”

“…We now apply the 3-point formalism to a laser-driven Gaussian potential that is used as a 1D simplistic model for the Cl − ion [28]. This model has been extensively studied, and in particular it was found [18] that there is an avoided crossing for the laser frequency of ω = 0.0925 au (KrFl) and a laser field amplitude of ε = 0.043 au. As avoided crossings are the precursors of the EP, we have applied the 3-point method and easily found an EP at ω EP 0.092 2252 au and ε EP 0.042 549 a.u.…”

Quasibound states in a chaotic molecular system

“…However, no attempt has so far been made to connect the quasibound states in HOCl to the underlying classical dynamics. Recent studies of electron waveguides and laser-driven atomic systems suggest that both stable and unstable POs as well as homoclinic and heteroclinic tangles in the classical phase space can influence the quasibound states of a system [8,9]. The purpose of the current paper is to examine the structure and lifetime of quasibound states using a 2D model of HOCl and to illustrate how these states are influenced by the classical dynamics of the system.…”