Effect of confined one-gluon-exchange potential and instanton-induced interaction on nucleon–nucleon interaction

The effect of confined one-gluon-exchange potential and instanton-induced interaction potential in the singlet(~1S_0) and triplet(~3S_1) channels for nucleon–nucleon interaction has been investigated in the framework of the relativistic harmonic model using the resonating group method in the adiabatic limit with the Born–Oppenheimer approximation. The contributions of the different components of the interaction potentials have been analyzed.     

The effects of electron–phonon interaction on anisotropic RKKY interaction in graphene nanoribbon

We study the Ruderman–Kittle–Kasuya–Yosida (RKKY) interaction in doped armchair graphene nanoribbon. The effects of both external magnetic field and electron-Holstein phonon on RKKY interaction have been addressed. RKKY interaction as a function of distance between localized moments has been analyzed. It has been shown that a magnetic field along the z-axis mediates an anisotropic interaction which corresponds to a XXZ model interaction between two magnetic moments. In order to calculate the exchange interaction along arbitrary direction between two magnetic moments, we should obtain both transverse and longitudinal static spin susceptibilities of armchair graphene nanoribbon in the presence of electron-phonon coupling and magnetic field. The spin susceptibility components are calculated using the spin dependent Green’s function approach for Holstein model Hamiltonian. The effects of spin polarization on the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show the influences of magnetic field on the spatial behavior of in-plane and longitudinal RKKY interactions are different in the presence of magnetic field.     

On the ηN interaction strength

We show that the binding energy of the η-mesic nucleus does not increase monotonically with the ηNN¹ (1535) coupling constant. This feature is a direct consequence of the unitarity constaint on the ηN interaction.     

Constraint on anomalous 4ν interaction

The features of a hypothetical 4ν interaction considered as the possible reason for massive-neutrino instability required in the cosmological scenario that involve neutrino dark matter are discussed. New constraints on the 4ν-interaction constant G _χ are obtained: G _χ<(15–42)G _F for m _χ>G _Z (G _F is the Fermi constant of weak interaction; m _χ is the mass of the 4ν-interaction gauge boson, also known as χ boson; and m _Z is the Z-boson mass) and G _χ<(2.8–5.6)G _F for m _χ?G _Z . These constraints virtually rule out the 4ν interaction as a possible version of solution to the cosmological neutrino-instability problem.     

Dynamical Casimir–Polder atom-surface interaction

We have calculated dynamical Casimir–Polder force between a moving ground state atom and a flat polarizable surface. The velocity of an atom can be close to the velocity of light. The material properties are taken into account using a single oscillator model of the atomic dynamic polarizability and the Drude dielectric function of a metal substrate. The limit cases of nonrelativistic velocities and an ideal metal substrate are also considered. We have found specific dependence of the calculated forces on the velocity (energy), distance and material properties.     

Spatiotemporal binary interaction and designer quasi-particle condensates

We introduce a new integrable model to investigate the dynamics of two component quasi-particle condensates with spatiotemporal interaction strengths. We derive the associated Lax pair of the coupled Gross-Pitaevskii （GP） equation and construct matter wave solitons, We show that the spatiotemporal binary interaction strengths not only facilitate the stabilization of the condensates, but also enables one to fabricate condensates with desirable densities, geometries, and properties, leading to the so-called ＂designer quasi-particle condensates＂.     

Tailoring electron–phonon interaction in nanostructures

Efficient design of optoelectronic devices based on electron intersubband transitions depends critically on the knowledge of the intersubband relaxation times which in turn, depends on electron scattering with LO and acoustic phonons. In this article the intersubband scattering time associated with electron–acoustic-phonon interaction has been discussed in terms of phonon mode quantization and phonon confinement with describing the acoustic phonon dispersion relation in detail by introducing the cut-off frequency for each mode. It has been shown that the quantization of acoustic phonon modes lead to an enhancement in electron–phonon scattering time in AlGaAs quantum well structures. Based on the presented model, a new tailoring method has presented to adjust the electron–phonon scattering time in intersubband-transition-based structures while keeping the electronic properties unaltered. Also, we illustrated that for a quantum well with subband energy separation of ∼30 meV, the intersubband scattering time with acoustic-phonon-assisted transitions could be tailored from ∼120 ps to increased value of ∼400 ps or reduced value of ∼45 ps by inserting a 1 nm-thickacoustically soft or hard layers, respectively, while keeping the same the initial energy separation.     

Entanglement transfer via the Raman atom-cavity-field interaction

For the Raman interaction between an atom and a two-mode cavity field prepared in the state |01> or |10> , the atom and the field can be disentangled periodically. Such a property of Raman atom-field interaction allows the full entanglement transfer among many atoms and bimodal cavities. In the calculations, each atom is assumed to interact with its own cavity at a different time and so non-identical atoms can be treated conveniently. Entanglement sudden death is discussed too. Though atom-field interaction greatly changes the values of the concurrence for two atoms, configuration of the concurrence is almost not affected. When there is entanglement sudden death, atoms and cavities can still be entangled with one another. However, full entanglement transfer cannot be achieved for such systems with Raman atom-field interaction.     

Magnetization reversal within Dzyaloshinskii—Moriya interaction under on-site Coulomb interaction in BiCrO3

First-principals calculations show that magnetization reversal is accompanied by the opposite sense of rotation of the neighboring oxygen octahedra along the [1 1 1] direction which is called the antiferrodistortive displacement in BiCrO3. The coupling between magnetization and antiferrodistortive distortion is mainly caused by Dzyaloshinskii- Moriya interaction which is driven by the eg-eg states antiferromagnetic interaction in Cr-3d. A critical value of on-site Coulomb interaction prohibiting the Dzyaloshinskii-Moriya interaction and thus the magnetization reversal is found to be 1.3 eV.     

Effects of dipole-dipole interaction on entanglement transfer

A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole-dipole （dd） interaction between two atoms on the atom-atom entanglement and mode--mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled.     

Double hypernuclei and the λ-gL interaction

The binding energy of the double hypernuclei \(\mathop \Lambda \limits^6 \Lambda\) He, \(\mathop {\Lambda \Lambda }\limits^{10}\) Be, and \(\mathop {\Lambda \Lambda }\limits^{11}\) Be and of the corresponding hypernuclei are calculated using the λ+λ+ core model. The parameters of the λ-λ interaction are found and compared to those of the λ-N interaction.     

Indirect interaction of Mössbauer nuclei

An expression is deduced for the operator of the indirect interaction of nuclei via the electromagnetic field. The properties of Mössbauer nuclei are described within the pseudospin formalism, which is usually used in the theory of optical two-level systems. The indirect interaction of pseudospins is derived by a method adopted from the theory of superconductivity. It is found that the potentials of this interaction involve terms decreasing as r ^?3, r ^?2, and r ^?1. The estimates demonstrate that the two-particle interaction can contribute significantly to the width of the resonance line, for example, in crystals whose cells contain thulium nuclei.     

Study on the optimum parameters for laser-solid interaction

The optimum parameters for laser propulsion are discussed, such as laser induced pressure on targets, interaction parameters (Cm, Isp) and optimum laser intensity Is, etc. It is verified that the larger laser power density will induce higher thrusting force. It is also found that, to drive a 1.010-kg target during confined laser ablation in vacuum and a 17.45-g one during direct laser ablation in air at the standard pressure, the needed minimum power intensities are on the same order of magnitude.     

Dynamical van der Waals atom–surface interaction

We obtained new nonrelativistic expression for the dynamical van der Waals atom–surface interaction energy of a very convenient form for different applications. It is shown that classical result (Ferrell and Ritchie, 1980) holds only for a very slowly moving atom. In general case, the van der Waals atom–surface interaction energy manifests strong nonlinear dependence on the velocity and distance. In close vicinity of metal and dielectric surfaces and velocities ranging from 1 to 10 bohr units the dynamical van der Waals potential proves to be several times lower than in the static case and goes to the static values with increasing the distance and (or) decreasing the velocity.     

Repulsive bubble–bubble interaction in ultrasonic field

The bubble–bubble interaction(BBI) is attractive in most cases, but also could be repulsive. In the present study,three specific mechanisms of repulsive BBI are given. The great contribution to the repulsive BBI is derived from the large radius of the bubble catching the rebound point of the other bubble. For "elastic" bubble and "inelastic" bubble, with the increase of the phase shift between two bubbles, the BBI changes from attractive to repulsive, and the repulsion can be maintained. For both "elastic" bubbles, the BBI alternates between attractive interaction and repulsive interaction along the direction where the ambient radius of one of bubbles increases. For stimulating bubble and stimulated bubble, the BBI can be repulsive. Its property depends on the ambient radii of bubbles. In addition, the distribution of the radiation forces in ambient radius space shows that the BBI is sensitive to the size of bubble and is complex because the bubbles are not of the same size in an ultrasonic field. Finally, as the distance increases or decreases monotonically with time, the absolute value of the BBI decreases or increases, correspondingly. The BBI can oscillate not only in strength but also in polarity when the distance fluctuates with time.     

Effect of strong interaction inpdμ-mesic molecules

It is shown that the inclusion of the exchange interaction between nuclei of a mesic molecule removes the degeneracy of the Coulomb levels and doubles the levels. For the ground state of thepd-molecular ion the splitting is estimated to amount to E10^–2 eV. Possible experiments for detection of this effect are discussed.     

Chern–Simons particles with nonstandard gravitational interaction

The model of nonrelativistic particles coupled to nonstandard (2+1)-gravity is extended to include Abelian or non-Abelian charges coupled to Chern–Simons gauge fields. Equivalently, the model may be viewed as describing the (Abelian or non-Abelian) anyonic dynamics of Chern–Simons particles coupled, in a reparameterization invariant way, to a translational Chern–Simons action. The quantum 2-body problem is described by a nonstandard Schr?dinger equation with a noninteger angular momentum depending on energy as well as particle charges. Some numerical results describing the modification of the energy levels by these charges in the confined regime are presented. The modification involves a shift as well as splitting of the levels. Received: 16 March 2001 / Published online: 13 June 2001     

Is the weak interaction constant really constant?

A comparison is made of the probability of the process of two-neutrino double beta decay for ⁸²Se and ⁹⁶Zr in direct (counter) and geochemical experiments. The experimental data for ¹³⁰Te are also analyzed. It is shown that the probability is systematically lower in geochemical experiments, which characterize the probability of (2) decay 10⁹ y ago. It is proposed that this could be due to a change in the weak interaction constant with time. It is proposed that a series of new, precise measurements be performed with the aid of counters and geochemical experiments.