相关论文: Quantum and Classical Orientational Ordering in So…
We show that the dependence of high-order harmonic generation (HHG) on the molecular orientation can be understood within a theoretical treatment that does not involve the strong field of the laser. The results for H_2 show excellent…
The dynamics of non-polar diatomic molecules interacting with a far-detuned narrow-band laser field, that only may drive rotational transitions, is studied. The rotation of the molecule is considered both classically and quantum…
The liquid, plastic crystalline and ordered crystalline phases of CBr$_4$ were studied using neutron powder diffraction. The measured total scattering differential cross-sections were modelled by Reverse Monte Carlo simulation techniques…
We derive the nonlinear optical conductivity of an isotropic electron fluid at frequencies below the interparticle collision rate. In this regime, governed by hydrodynamics, the conductivity acquires a universal form at any temperature,…
Motivated by the recent neutron diffraction experiment on $YVO_3$, we consider a microscopic model where each $V^{3+}$ ion is occupied by two 3d electrons of parallel spins with two fold degenerate orbital configurations. The mean field…
We present a Path Integral Monte Carlo calculation of the first three moments of the displacement-displacement correlation functions of solid neon at different temperatures for longitudinal and transverse phonon modes. The Lennard-Jones…
Analyses of high energy elastic pp and $\bar pp$ scattering data from CERN ISR and SPS Collider seem to provide strong evidence in favor of the gauged nonlinear sigma-model of the nucleon. This model describes the nucleon as a topological…
Solution-grown single crystals of Fe2OBO3 were characterized by specific heat, Mossbauer spectroscopy, and x-ray diffraction. A peak in the specific heat at 340 K indicates the onset of charge order. Evidence for a doubling of the unit cell…
We develop a multi order parameter mean-field formalism for systems of coupled quantum rotors. The scheme is developed to account for systems where {\it ortho-para} distinction is valid. We apply our formalism to solid H$_2$ and D$_2$. We…
Starting from an ideal crystalline state, we numerically study a nonequilibrium dynamical order- disorder transition promoted by the application of a periodic shearing protocol at low temperatures in model systems in two and three…
In the last decade five new ice phases were experimentally prepared. Two of them are empty clathrate hydrates and three of them represent hydrogen ordered counterparts of previously known disordered ice phases. Here, we report on hydrogen…
Boron bulk crystals are marked by exceptional structural complexity and unusual related physical phenomena. Recent reports of hydrogenated $\alpha$-tetragonal and a new $\delta$-orthorhombic boron B$_{52}$ phase have raised many fundamental…
The recent discovery of phase IV of solid hydrogen and deuterium consisting of two alternate layers of graphenelike three-molecule rings and unbound H2 molecules have generated great interests. However, vibrational nature of phase IV…
We present a study of the structural properties of the crystalline phases for a planar bilayer of particles interacting via repulsive Yukawa potentials in the weak screening region. The study is done with Monte Carlo computations and the…
We study the effect of thermal fluctuations in the XY-model on a surface with non vanishing mean curvature and zero Gaussian curvature. Unlike Gaussian curvature that typically frustrates orientational order, the extrinsic curvature of the…
Unconventional phases often occur where two competing mechanisms compensate. An excellent example is the ionic Hubbard model where the alternating local potential $\delta$, favoring a band insulator (BI), competes with the local repulsion…
We introduce a phenomenological theory for a new class of soft active fluids, with the ability to synchronise. Our theoretical framework describes the macroscopic behaviour of a collection of interacting anisotropic elements with cyclic…
We present the theory of orbital ordering in orbital-degenerate itinerant electron systems. After proposing the criterion of instability for orbital ordering or orbital density wave ordering, we find that the orbital and the spin-orbital…
In this paper, the off-diagonal geometric phase of thermal state in hydrogen atom under the effects of external magnetic field is considered. Increasing temperature tends to suppress the off-diagonal geometric phase, including 1-order and…
Relationship among Wigner crystal, charge order and Mott insulator is studied by the path-integral renormalization group method for two-dimensional lattices with long-range Coulomb interaction. In contrast to Hartree-Fock results, the solid…