Orientational quantum revivals induced by a single-cycle terahertz pulse

TL;DR

This paper demonstrates how a single-cycle terahertz pulse can induce orientational quantum revivals in molecules, offering a new method for quantum control with potential applications across physics and chemistry.

Contribution

It introduces a novel approach to generate orientational quantum revivals using a single-cycle THz pulse without the sudden-impact limit, supported by analytical and numerical analysis.

Findings

Strong field-free OQR achieved in HCN molecules.

Multiphoton processes enhance OQR beyond ladder-climbing mechanisms.

Explicit three-state model explains the quantum mechanism.

Abstract

The phenomenon of quantum revivals resulting from the self-interference of wave packets has been observed in several quantum systems and utilized widely in spectroscopic applications. Here, we present a combined analytical and numerical study on the generation of orientational quantum revivals (OQRs) exclusively using a single-cycle THz pulse. As a proof of principle, we examine the scheme in the linear polar molecule HCN with experimentally accessible pulse parameters and obtain strong field-free OQR without requiring the condition of the sudden-impact limit. To visualize the involved quantum mechanism, we derive a three-state model using the Magnus expansion of the time-evolution operator. Interestingly, the THz pulse interaction with the electric-dipole moment can activate direct multiphoton processes, leading to OQR enhancements beyond that induced by a rotational ladder-climbing mechanism from the rotational ground state. This work provides an explicit and feasible approach toward quantum control of molecular rotation, which is at the core of current research endeavors with potential applications in atomic and molecular physics, photochemistry, and quantum information science.