Nonadiabatic ponderomotive potentials

Abstract

An approximate integral of the Manley-Rowe type is found for a particle moving in a highfrequency field, which may interact resonantly with natural particle oscillations. An effective ponderomotive potential is introduced accordingly and can capture nonadiabatic particle dynamics. We show that nonadiabatic ponderomotive barriers can trap classical particles, produce cooling effect, and generate one-way walls for resonant species. Possible atomic applications are also envisioned.

Positive and negative effective mass of classical particles in oscillatory and static fields

“…Results similar to those in this Appendix were obtained earlier for particle motion in a dc magnetic field [3,35,41], oscillations in nonrelativistic high-frequency waves [8,93], and laser-driven relativistic electron dynamics in vacuum [16,24,25]. In the main text, we make use of the general form of the theorem (A6), which contains the earlier results as particular cases.…”

“…In the adiabatic regime, one can map out the quiver dynamics by changing variables [1,2,3,4,5,6,7,8]; hence the guiding center is treated as a "dressed", or quasi-particle. Suppose, for now, that the background fields causing the oscillations do not vary along the trajectory.…”

“…A large number of problems connected with multiscale adiabatic dynamics of classical particles in oscillatory and static fields enjoy critical simplification within the guiding-center approach, which allows separating fast oscillatory motion of the particles from their slow translational motion [1,2,3,4,5,6,7,8,9]. Often, the average forces on a guiding center are then written in terms of effective potentials Ψ, such as ponderomotive [7,10,11,12], diamagnetic [13], or others [8,12].…”

“…Often, the average forces on a guiding center are then written in terms of effective potentials Ψ, such as ponderomotive [7,10,11,12], diamagnetic [13], or others [8,12]. Yet the applicability of the potential approximation is limited to, at most, nonrelativistic interactions, another drawback being the unphysical difference in fictitious fields −∇Ψ seen by different species.…”

Direct-current-like phase space manipulation using chirped alternating current fields

“…However, Eq. ͑17͒ presumes the driven particle is far enough out of resonance for adiabatic analysis to hold; as the singularity at resonance is approached the particle dynamics becomes nonadiabatic, and the form of the ponderomotive potential changes, 34 so the strength of ⌽ P cannot be increased without limit.…”