SearcharxivSearch

arXiv subjects

D. Meng

Publications and source records attributed to D. Meng.

3 recordsLinked to original sources

Laser-intensity-spike-dominated hot electron generation from two-plasmon decay instability driven by moderate-bandwidth pulses

Our direct-drive-relevant experiments on the low-coherence Kunwu laser facility identify two-plasmon decay (TPD) as the primary source of hot electrons, and demonstrate for the first time that broadband laser pulses enhance TPD. Using particle-in-cell simulations, we attribute this TPD enhancement and the consequent hot electron production to stochastic intensity spikes inherent in broadband laser fields, robust in both weakly- and strongly-driven regimes. These findings suggest that mitigating hot electron generation requires suppressing these intensity spikes.

physics.plasm-ph

Stern-Gerlach interferometry in three dimensions: the role of transverse fields

We show that superficially similar implementations of Stern-Gerlach Interferometers (SGIs) are expected to differ dramatically in their sensitivity to fields transverse to the primary acceleration direction. These transverse fields unavoidably accompany any static magnetic or electric field gradients, and have been shown by Comparat [Phys. Rev. A 101, 023606 (2020)] to limit the precision application of SGIs. As a concrete example, we consider SGIs with ultracold Rb Rydberg atoms accelerated by spatially-varying electric fields. We find that the deleterious effect of transverse fields imply that only some implementations (sequences of field gradients, internal state swaps, and so-on) may exhibit fringes with high visibility.

physics.atom-ph

Nanoscale ice fracture by molecular dynamics simulations

In this work, we conducted molecular dynamics simulations to study the fracture mechanism of ice crystals in a bulk phase and at ice-ice interfaces at the atomistic scale. We show that there exists a narrow disordered interfacial layer between two Ih ice structures. The width of the interfacial layer is determined to be about the size of two water molecules. Upon deformation, the stress response of ice at interface show significantly anisotropic behaviors depending on the direction of deformation. Bulk-like behavior is observed when direction of deformation being orthogonal to the direction of interfacial plane. Significantly smaller fracture stress and yield strain occurs if the deformation is along interfacial plane. This result illustrates the dominant role played by the small amount of disordered water molecules at interface in altering mechanical strength of an interfacial structure.

physics.chem-ph