相关论文: Spontaneous symmetry breaking by double lithium ad…
We study effects of different configurations of adsorbates on the vibrational modes as well as symmetries of polyacenes and poly-p-phenylenes focusing on lithium atom adsorption. We found that the spectra of the vibrational modes…
We study the spontaneous symmetry breaking due to adsorption of Lithium atoms on polyacenes and aromatic molecules consistent on carbon rings with edges closed by bond of hydrogen atoms. Hartree Fock and DFT calculations were made for…
We study the adsorption of Li to graphene flakes described as aromatic molecules. Surprisingly the out of plane deformation is much stronger for the double adsorption from both sides to the same ring than for a single adsorption, although a…
Graphene has received a great deal of attention and this has more recently extended to boron nitride sheets (BNS) with a similar structure. Both have hexagonal lattices and it is only the alternation of atoms in boron nitride, which changes…
The effect of increased electron-density (from adsorbed Li atoms) in polyacenes and in nano-ribbons with zig-zag edge is discussed in terms of resonance theoretical considerations and in terms edge-localized frontier molecular orbitals. The…
A pseudo-Jahn-Teller model describing central atom distortions is proposed for endohedral fullerenes of the form A@C$_{60}$ where A is either a rare gas or a metal atom. A critical (dimensionless) coupling $g_c$ is found, below which the…
The ability of metal adsorption to transfer charge to the surface of single molecular carbon sheets is explored in this paper. Though other metals are considered we basically will deal with Lithium We concentrate on fairly small sheets and…
Using first-principles Density Functional Theory calculations, we showed that electronic and magnetic properties of bare and Ti adatom adsorbed single-layer silicene and germanene, which are charged or exerted by a perpendicular electric…
The adsorption of polydisperse ideal polymer chains is shown to be sensitive to the large N tail of the distribution of chains. If and only if the number of chains decays more slowly than exponentially then there is an adsorption transition…
The onset of distortion in one-dimensional monatomic chains with partially filled valence bands is considered to be well-established by the Peierls theorem, which associates the distortion with the formation of a band gap and a subsequent…
There exist two types of structural instability in polyacene: double bonds in a cis pattern and those in a trans pattern. They are isoenergetic but spectroscopically distinct. We demonstrate optical characterization and manipulation of…
Matter is coupled to three-dimensional gravity such that the topological phase is allowed and the (anti-) de Sitter or Poincar\'e symmetry remains intact. Spontaneous symmetry breaking to the Lorentz group occurs if a scalar field is…
We propose that several mechanisms contribute to friction in a polymer melt adsorbed at a structured surface. The first one is the well known disentanglement of bulk polymer chains from the surface layer. However, if the surface is ideal at…
We prove a strong form of spontaneous breaking of rotational symmetry for a simple model of two-dimensional crystals with random defects in thermal equilibrium at low temperature. The defects consist of isolated missing atoms.
Creation and manipulation of non-classical states of light is rapidly becoming the focus of modern attosecond science. Here, we demonstrate numerically how interaction with such states can trigger the emergence of a many-body system with…
Linearization of a Hamiltonian system around an equilibrium point yields a set of Hamiltonian-symmetric spectra: If $\lambda$ is an eigenvalue of the linearized generator, $-\lambda$ and $\bar{\lambda}$ (hence, $-\bar{\lambda}$) are also…
In a physical system undergoing a continuous quantum phase transition, spontaneous symmetry breaking occurs when certain symmetries of the Hamiltonian fail to be preserved in the ground state. In the traditional Landau theory, a symmetry…
Spontaneous symmetry breaking is central to our understanding of physics and explains many natural phenomena, from cosmic scales to subatomic particles. Its use for applications requires devices with a high level of symmetry, but engineered…
We study spontaneous symmetry breaking in a system of two parallel quasi-one-dimensional traps, equipped with optical lattices (OLs) and filled with a Bose-Einstein condensate (BEC). The cores are linearly coupled by tunneling. Analysis of…
We propose a model for chiral polymerisation and investigate its symmetric and asymmetric solutions. The model has a source species which decays into left- and right-handed types of monomer, each of which can polymerise to form homochiral…