Formation Mechanisms of Electronically Excited Nitrogen Molecules from N + N and N + N + N Collisions Revealed by Full-Dimensional Potential Energy Surfaces.

This work reports six new full-dimensional adiabatic potential energy surfaces (PESs) of the N system (four A″ states and two A″ states) at the MRCI + Q/AVQZ level of theory that correlated to N(Σ) + N(), N(Σ) + N(), N(Σ) + N(), N(Π) + N(), N(Δ) + N(), and N() + N() + N() channels. The neural networks with a proper account of the nuclear permutation invariant symmetry of N were employed to fit the PESs based on about 4000 points. The accuracy of the PESs was validated by excellent agreement on the equilibrium bond length, vertical excitation energy, and dissociation energy with experimental values.

Enhancement of electron-impact ionization induced by warm dense environments.

Studies have shown significant discrepancies between the recent experiment [Berg et al., Phys. Rev.

Local field correction to ionization potential depression of ions in warm or hot dense matter.

An analytical self-consistent approach was recently established to predict the ionization potential depression (IPD) in multicomponent dense plasmas, which is achieved by considering the self-energy of ions and electrons within the quantum statistical theory. In order to explicitly account for the exchange-correlation effect of electrons, we incorporate the effective static approximation of local field correction (LFC) within our IPD framework through the connection of dynamical structure factor. The effective static approximation poses an accurate description for the asymptotic large wave number behavior with the recently developed machine learning representation of static LFC induced from the path-integral Monte Carlo data.

Phase diagrams and multistep condensations of spin-1 bosonic gases in optical lattices.

Motivated by recent experimental processes, we systemically investigate strongly correlated spin-1 ultracold bosons trapped in a three-dimensional optical lattice in the presence of an external magnetic field. Based on a recently developed bosonic dynamical mean-field theory (BDMFT), we map out complete phase diagrams of the system for both antiferromagnetic and ferromagnetic interactions, where various phases are found as a result of the interplay of spin-dependent interaction and quadratic Zeeman energy. For antiferromagnetic interactions, the system demonstrates competing magnetic orders, including nematic, spin-singlet and ferromagnetic insulating phase, depending on longitudinal magnetization, whereas, for ferromagnetic case, a ferromagnetic-to-nematic-insulating phase transition is observed for small quadratic Zeeman energy, and the insulating phase demonstrates the nematic order for large Zeeman energy.