Intermolecular interactions probed by rotational dynamics in gas-phase clusters.

The rotational dynamics of a molecule is sensitive to neighboring atoms or molecules, which can be used to probe the intermolecular interactions in the gas phase. Here, we real-time track the laser-driven rotational dynamics of a single N molecule affected by neighboring Ar atoms using coincident Coulomb explosion imaging. We find that the alignment trace of N-N axis decays fast and only persists for a few picoseconds when an Ar atom is nearby.

Ultrafast photoinduced C-H bond formation from two small inorganic molecules.

The formation of carbon-hydrogen (C-H) bonds via the reaction of small inorganic molecules is of great significance for understanding the fundamental transition from inorganic to organic matter, and thus the origin of life. Yet, the detailed mechanism of the C-H bond formation, particularly the time scale and molecular-level control of the dynamics, remain elusive. Here, we investigate the light-induced bimolecular reaction starting from a van der Waals molecular dimer composed of two small inorganic molecules, H and CO.

Wave-Packet Surface Propagation for Light-Induced Molecular Dynamics.

Recent advances in laser technology have enabled tremendous progress in light-induced molecular reactions, at the heart of which the breaking and formation of chemical bonds are located. Such progress has been greatly facilitated by the development of an accurate quantum-mechanical simulation method, which, however, does not necessarily accompany clear dynamical scenarios and is rather computationally heavy. Here, we develop a wave-packet surface propagation (WASP) approach to describe the molecular bond-breaking dynamics from a hybrid quantum-classical perspective.

Stereodynamical Control of D Formation from the Bimolecular Photoreaction in the D-D Dimer.

We report the stereodynamic control of D formation from the laser-induced bimolecular reaction in a weakly bound D-D dimer via impulsive molecular alignment. Using a linearly polarized moderately intense femtosecond pump pulse, the D molecules in the dimer were prealigned prior to the bimolecular reaction triggered by a delayed probe pulse. The rotationally excited D in the dimer was observed to rotate freely as if it were a monomer.

Electron transfer in strong-field three-body fragmentation of ArKr trimers.

We experimentally studied the three-body fragmentation dynamics of a noble gas cluster (ArKr) upon its multiple ionization by an intense femtosecond laser pulse. The three-dimensional momentum vectors of correlated fragmental ions were measured in coincidence for each fragmentation event. A novel comet-like structure was observed in the Newton diagram of the quadruple-ionization-induced breakup channel of ArKr → Ar + Kr + Kr.

Design of multifunctional all-optical logic gates based on photonic crystal waveguides.

The explosive development of the big data era has driven the rapid growth of silicon photonics, and logic operators based on photonic circuits have also been intensively investigated. Photonic integrated logic operators possess a high degree of design freedom and novel prospects, and they are regarded as promising platforms for future signaling and data processing. In this work, considering all-optical logic operation with lower power consumption and a smaller device footprint, multifunctional all-optical logic gates based on silicon photonic crystal (PhC) waveguides and phase-encoded light beams are proposed and applied to realize several logic operators, including XNOR, XOR, NOR, AND gates as well as a half adder and half subtractor.