Carrier-envelope-phase (CEP) of sub-cycle ultraviolet (UV) pulse strongly influences the dynamics of quantum systems, but its characterization is not accessible experimentally. Here we investigate photodissociation of a diatomic molecule from its ground-rovibrational state in a linearly polarized weak sub-cycle UV pulse with a controlled CEP. The angular distribution of photofragments shows an asymmetric profile deviating from the well-known $${\cos }^{2}$$ cos 2 - or $${\sin }^{2}$$ sin 2 -like ones, which can be identified as a way to imprint CEP. We unveil that such an effect stems from the temporal neighboring rotational excitation by molecular permanent dipole interaction through the joint contributions between counter-rotating and rotating terms. This in turn, opens different pathways in photodissociation dynamics. Given that the temporal excitation between various states with close energies can be manipulated by CEP of sub-cycle UV pulses, our results pave ways for understanding and manipulating electron, nuclear and their joint dynamics with variation of CEP of attosecond pulses.

Based on the kinetic theory, improved T-matrix models for the continuous-slowing-down (CSD) and the linear-energy-transfer (LET) stopping powers are established at the same level, where multiple scattering effects and the related transverse deflection are accounted for consistently and systematically. The degree of deflection characterizing the extent of transverse deflection is defined by means of the ratio of these two stopping powers. Calculations for energy deposition and deflection of α particle in hot dense deuterium-tritium (DT) plasmas and also in hot dense DT plasmas mixed with carbon (C) impurity are performed. Multiple scattering effects and the resulting transverse deflection are demonstrated to have a significant influence on the stopping power of α particle, in particular, in mixtures containing different ions with large mass and charge asymmetry. It is shown that for DT plasma mixed with 5% C impurity, the range and penetration depth of the α particle are shortened by about 21% and 27%, respectively. Our models are found to be appropriate for the evaluation of stopping powers not only in weakly coupled plasmas but also in moderately degenerate and correlated plasmas. These results manifest that multiple scattering effects and the induced transverse deflection need to be taken into account in modeling the transport of α particle in hot dense plasmas relevant to inertial confinement fusions.

The study of the dynamics of molecular valence electrons and their coupling with nucleus motion is a frontier in ultrafast physics and ultrafast chemistry. Here, we investigate the behavior of valence electrons and nucleus wavepackets on a femtosecond time scale by the time-resolved strong-field ion momentum spectroscopy. Two orientation-dependent bond-breakages of N2O molecules from the same electronic state are studied, and the evolution of dipole moment during molecular breaking on the asymmetric Pzsum distribution is analyzed, and thus the electron localization during the molecules dissociating into ions and atoms is captured. The overall agreement between experimental and theoretical results for the orientation-dependent dissociation dynamics promotes the understanding of the evolution of nucleus wavepackets and provides a basis for the control of molecular ultrafast chemical reactions.

Real-time imaging of transient structure of the electronic excited state is fundamentally critical to understand and control ultrafast physics and chemistry. However, the coherent nuclear motion in a specific excited state is yet to be captured accurately. Here, snapshots of the vibrational wave-packets of the excited (A) and ground states (X) of D$\rm_{2}$O$^{+}$ were acquired simultaneously with sub-10 picometer and few-femtosecond spatiotemporal precision, using a novel approach based on electron recollision-assisted Coulomb explosion. We visualised large amplitude bending and stretching motions for the A state, which significantly increased $\rm \theta _{DOD}$ and R$\rm_{OD}$ by approximately 50$^\circ$ and 10 pm, respectively, within 8 fs after initial tunneling ionization. In contrast, for the X state, only the prominant stretching motion is initialised with a bond extension of 7 pm within 5 fs. Another higher excited state with an asymmetric folding structure is experimentally established, which can be efficiently populated via the excitation of electron recollision. We demonstrate the remarkable dynamical vibrational fingerprints of these excite states and pave the way towards to make a movie of excited state-resolved ultrafast molecular dynamics and light-induced chemical reaction.