Dynamics of polar polarizable rotors acted upon by unipolar electromagnetic pulses: From the sudden to the adiabatic regime

Abstract

We study, analytically as well as numerically, the dynamics that arises from the interaction of a polar polarizable rigid rotor with single unipolar electromagnetic pulses of varying length, $\Delta \tau$, with respect to the rotational period of the rotor, ${\tau }_r$. In the sudden, non-adiabatic limit, $\Delta \tau \ll {\tau }_r$, we derive analytic expressions for the rotor's wavefunctions, kinetic energies, and field-free evolution of orientation and alignment. We verify the analytic results by solving the corresponding time-dependent Schrödinger equation numerically and extend the temporal range of the interactions considered all the way to the adiabatic limit, $\Delta \tau \gg {\tau }_r$, where general analytic solutions beyond the field-free case are no longer available. The effects of the orienting and aligning interactions as well as of their combination on the post-pulse populations of the rotational states are visualized as functions of the orienting and aligning kick strengths in terms of populations quilts. Quantum carpets that encapsulate the evolution of the rotational wavepackets provide the space-time portraits of the resulting dynamics. The population quilts and quantum carpets reveal that purely orienting, purely aligning, or even-break combined interactions each exhibit a sui generis dynamics. In the intermediate temporal regime, we find that the wavepackets as functions of the orienting and aligning kick strengths show resonances that correspond to diminished kinetic energies at particular values of the pulse duration.

arXiv comment9 figures

References in corpus (19)

• The Magnus expansion and some of its applications
• Quantum wave packet revivals
• Efficient and long-lived field-free orientation of molecules by a single hybrid short pulse
• Making the best of mixed-field orientation of polar molecules: A recipe for achieving adiabatic dynamics in an electrostatic field combined with laser pulses
• Quantum resonances in selective rotational excitation of molecules with a sequence of ultrashort laser pulses
• WavePacket: A Matlab package for numerical quantum dynamics. I: Closed quantum systems and discrete variable representations
• Orientation of molecules via laser-induced anti-alignment
• Conservative chaotic map as a model of quantum many-body environment
• WavePacket: A Matlab package for numerical quantum dynamics. II: Open quantum systems, optimal control, and model reduction
• Semiclassical catastrophes and accumulative angular squeezing of a kicked quantum rotor
• Localization, quantum resonances and ratchet acceleration in a periodically-kicked $\mathcal{P}\mathcal{T}$-symmetric quantum rotator
• Hamiltonian ratchets with ultra-cold atoms
• Steering random walks with kicked ultracold atoms
• Supersymmetry identifies molecular Stark states whose eigenproperties can be obtained analytically
• Clones and other interferance effects in the evolution of angular momentum coherent states
• Supersymmetry and eigensurface topology of the planar quantum pendulum
• Supersymmetry and eigensurface topology of the spherical quantum pendulum
• Conditional quasi-exact solvability of the quantum planar pendulum and of its anti-isospectral hyperbolic counterpart
• Symmetric Tops Subject to Combined Electric Fields: Conditional Quasi-Solvability via the Quantum Hamilton-Jacobi Theory

Cited by in corpus (5)

• Quantum control of molecular rotation
• Long-lasting Molecular Orientation Induced by a Single Terahertz Pulse
• Quantum dynamics of a planar rotor driven by suddenly switched combined aligning and orienting interactions
• Topological charges of periodically kicked molecules
• Quantum dynamics of a polar rotor acted upon by an electric rectangular pulse of variable duration