"Signal Energy" of an Excited Dipolar Bose Gas driven by an Oscillating Dimple

It is known that dipolar Bose-Einstein condensates (DBECs) display rich and fascinating features that are not observable in nonpolar BECs (Lahaye et al., Rep. Prog. Phys. 72, 126401 (2009)). As such, the present examination studies the dynamics of a DBEC, being motivated by the work of Sabari and Kumar (Eur. Phys. J. D 72, 48 (2018)) who examined the effect of an oscillating obstacle in a DBEC. We thus examine the "signal energy" of a trapped DBEC that is driven by an oscillating dimple potential. For this purpose we numerically solve the time-dependent Gross-Pitaevskii equation. The signal energy is related to the energy spectral density. It is demonstrated that the signal energy displays parametric resonances (PRs) at specific values of the dipole-dipole interaction parameter that can be controlled via the trapping geometry. The spacings between these values have been found to reveal information about the energy level structure of the external trap. The dynamics of the harmonic-oscillator (HO)-states occupancy obtainable from the modal coefficients C_n(t) arising in the decomposition of the wave function Ψ(x;t) = ∑_n=0 C_n(t) φ_n (x), where φ_n (x) is the usual HO function, as well as the phase-mismatch between C₀(t) and C₁(t) have been found to display challenging features at PR.