相关论文: Nonlinear Optical Response of C60 Molecules
The multiplet structure induced by the Coulomb interactions in C$_{60}^{n-}$ ($n = 1 - 12$) is analyzed. The partially ocuppied LUMO gives rise to a set of levels which fill a relatively wide band ( $\approx 2-3$ eV ). A large ($\sim 1$ eV)…
The Pauli rearrangement potential given by the second-order diagram is evaluated for a nucleon optical model potential (OMP) with $G$ matrices of the nucleon-nucleon interaction in chiral effective field theory. The results obtained in…
A relationship between the Coulomb inclusive break-up probability and the radiative capture reaction rate for weakly-bound three-body systems is established. This direct link provides a robust procedure to estimate the reaction rate for…
The Coulomb interaction between the two protons is included in the calculation of three-nucleon hadronic and electromagnetic reactions using screening and renormalization approach. Calculations are done using integral equations in momentum…
A theory of optical excitations by using a tight binding model with long-range Coulomb interactions is developed. The model is applied to a C60 molecule and a cluster, and is treated by the Hartree-Fock approximation followed by a…
We present a general method for determining screened Coulomb parameters in molecular assemblies, in particular organic molecular crystals. This allows us to calculate the interaction parameters used in a generalized Hubbard model…
The nonlinear magnetic $\chi_{3}$ and spin-glass $\chi_{sg}$ susceptibilities in zero applied field are obtained, from tempered Monte Carlo simulations, for three different spin glasses (SGs) of Ising spins with quenched site disorder. We…
Molecular exciton effects in the neutral and maximally doped C$_{60}$ (C$_{70}$) are considered using a tight binding model with long-range Coulomb interactions and bond disorder. By comparing calculated and observed optical spectra, we…
In this paper we first derive a Coulomb Hamiltonian for electron--electron interaction in quantum dots in the Heisenberg picture. Then we use this Hamiltonian to enhance a Bloch model, which happens to be nonlinear in the density matrix.…
In recent years, there has been growing interest in non-Hermitian phenomena in low-symmetry conductors, particularly optical gain driven by electro-optic effects. Conventional semiclassical treatments typically attribute these effects to…
The leading order nonlinear (NL) susceptibility, $\chi_3$, in a paramagnet is negative and diverges as $T \rightarrow 0$. This divergence is destroyed when spins correlate and the NL response provides unique insights into magnetic order.…
We have investigated the optical response of superradiant atoms, which undergoes three different damping mechanisms: radiative dissipation ($\gamma_r$), dephasing ($\gamma_d$), and nonradiative dissipation ($\gamma_n$). Whereas the roles of…
We adapted a recently proposed framework to characterize the optical response of interacting electrons in solids in order to expedite its computation without compromise in accuracy at the microscopic level. Our formulation is based on…
We observe a nonlinear optical process in a gas of cold atoms that simultaneously displays the largest reported fifth-order nonlinear susceptibility \chi^(5) = 1.9x10^{-12} (m/V)^4 and high transparency. The nonlinearity results from the…
Molecular exciton effects in the neutral and maximally doped C60 (C70) are considered using a tight binding model with long-range Coulomb interactions and bond disorder. By comparing calculated and observed optical spectra, we conclude that…
The predominant methods currently used to determine nonlinear optical constants like the nonlinear refractive index n2 or chi3 rely mostly on experimental, open and closed z-scan techniques and beam deflection methods. While these methods…
We develop a theoretical description of Coulomb interactions between trions (charged excitons) that define a nonlinear optical response in doped two-dimensional semiconductors. First, we formulate a microscopic theory of trion-trion…
We calculate numerically the quasiparticle effective mass (m*) renormalization as a function of temperature and electron density in two- and three-dimensional electron systems with long-range Coulomb interaction. In two dimensions, the…
Small organic molecules with a {\pi}-conjugated system that consists of only a few double or triple bonds can have significantly smaller optical excitation energies when equipped with donor- and acceptor groups, which raises the quantum…
Magnetic susceptibility $\chi$ of pristine and brominated arc-produced sample of multiwall carbon nanotubes was measured from 4.2 to 400 K. An additional contribution $\Delta \chi(T)$ to diamagnetic susceptibility $\chi(T)$ of carbon…