The effective Hamiltonian for the Renner-Teller effect

A derivation of the effective vibronic Hamiltonian for a linear triatomic molecule in a Π electronic state within the harmonic approximation is presented. In addition to the well-established vibrational and Renner-Teller coupling terms, there is a small term which has been overlooked before. The form of this term is derived and the parameter involved, g_K, is related to other observable quantities. Several experimental examples are presented which demonstrate that the extra term is needed to reproduce the vibronic levels in Π electronic states, the contribution being of the order of a few cm^?1.     

Josephson effect in ferromagnetic superconductors

The DC Josephson effect in ferromagnetic superconductors is theoretically studied in the presence of external magnetic fields. In addition to the usual term for the Josephson tunneling current, a new term expressing the pair tunneling current induced by the magnetization appears. The amplitude and period of the Fraunhofer pattern of the maximum Josephson current drastically diminish near the phase transition temperature for the magnetization bound around the junction.     

Incomplete Meissner effect of triplet superconductivity

The magnetic properties of a triplet superconductor are investigated using a phenomenological Ginzburg-Landau theory. Due to the presence of a paramagnetic term in the free energy arising from the energy required to flip the spins of a triplet pair by the magnetic field, the system does not exhibit a complete Meissner effect below T_c. This paramagnetic contribution to the magnetization is stabilized by the non-linear terms in the free energy, and for certain values of the parameters, can even cancel the diamagnetic term. The results are discussed in terms of the Anderson- Morel and Balian-Werthamer states.     

A synapse memristor model with forgetting effect

In this Letter we improved the ion diffusion term proposed in literature [13] and redesigned the previous model as a dynamical model with two more internal state variables ‘forgetting rate’ and ‘retention’ besides the original variable ‘conductance’. The new model can not only describe the basic memory ability of memristor but also be able to capture the new finding forgetting behavior in memristor. And different from the previous model, the transition from short term memory to long term memory is also defined by the new model. Besides, the new model is better matched with the physical memristor (Pd/WOx/W) than the previous one.     

On the nielsen-taylor effect in the diffusion thermopower of dilute alloys

It is suggested that the electron-phonon vertex correction to the electron-impurity scattering gives rise to an additional term in the diffusion thermopower of dilute alloys at low temperatures. The absolute magnitude of the additional term is similar to the Nielsen-Taylor term. The experiment which can detect these effects is investigated.     

Novel effect induced by spacetime curvature in quantum hydrodynamics

The interplay between quantum fluctuation and spacetime curvature is shown to induce an additional quantum-curvature (QC) term in the energy-momentum tensor of fluid using the generalized framework of the stochastic variational method (SVM). The QC term is necessary to satisfy the momentum conservation but the corresponding quantum hydrodynamics is not necessarily cast into the form of the Schrödinger equation, differently from the case of the Euclidean spacetime. This seems to suggest that the existence of the Hilbert space is not a priori requirement in the quantization of curved spacetime systems. As an example, we apply the Friedmann-Robertson-Walker (FRW) metric and show that this term contributes to the cosmological acceleration although it is too small in the present non-relativistic toy model.     

The effect of colored glue in the charmonium wave function

Using an adiabatic approximation and the MIT bag model, we examine the effect of including a term in the charmonium wave function which contains one quantum of the lowest mode of the transverse gluon field in addition to the quark and antiquark. The amplitude of this term is calculated in perturbation theory, and its presence leads to a significant reduction in magnetic dipole transition rates with no corresponding reduction in electric dipole transitions. Although going in the right direction, the effect is not large enough to explain the discrepancy with the experimental M1 rates.     

Sliding in a piecewise-smooth dynamical system with a hold-on effect

In this paper, we study a piecewise-smooth dynamical system of a Filippov type that has a specific discontinuity in the form of a hold-on term. The system resembles a driven dry-friction oscillator with the difference that the magnitude of the friction depends on the value of a local maximum of the oscillator displacement. Due to the hold-on term, the definition of the sliding region is not trivial. Along with a sliding region that is found analytically and is valid for any orbits, there exists a sliding region that we name ‘virtual’ because it is specific for each particular orbit. The existence of the virtual sliding region is explained by the specific discontinuity — the hold-on term — and the behavior associated with the sliding region and its boundaries can be considered as a new type of sliding-associated behavior.     

非均匀光纤中梯度项对模式的影响

对弱导非均匀折射率分布光纤的严格理论分析表明,显然在纵向场分量的标量波动方程中能够保留▽δ梯度项,但同时在横向场分量的方程中必须略去梯度项.并以TM模为例,给出了梯度项影响的具体表达式;消除了TM与TE模式之间的简并,明确了单模工作条件.     

The effect of nonlinearity on unstable zones of Mathieu equation

Mathieu equation is a well-known ordinary differential equation in which the excitation term appears as the non-constant coefficient. The mathematical modelling of many dynamic systems leads to Mathieu equation. The determination of the locus of unstable zone is important for the control of dynamic systems. In this paper, the stable and unstable regions of Mathieu equation are determined for three cases of linear and nonlinear equations using the homotopy perturbation method. The effect of nonlinearity is examined in the unstable zone. The results show that the transition curves of linear Mathieu equation depend on the frequency of the excitation term. However, for nonlinear equations, the curves depend also on initial conditions. In addition, increasing the amplitude of response leads to an increase in the unstable zone.     

Dynamical origin of the quantum Zeno effect

The quantum Zeno effect is often studied and understood in term of nonunitary evolutions, involving projections à la von Neumann (measurements). We propose a dynamical explanation of this effect, which involves only unitary operators. The limit of infinitely frequent measurements is critically discussed: it is unphysical, yet interesting and peculiar.     

The effect of diffusion in a new viscous continuum traffic model

In this Letter, we propose a new continuum traffic model with a viscous term. The linear stability condition for viscous shock waves is derived. We derive the Korteweg-de Vries (KdV) equation near the neutral stability line. Then we investigate the effect of the viscous term by numerical simulations. The results show that viscosity may induce oscillations and the amplitude of the oscillation increases as the viscosity coefficient increases. This agrees with the linear stability condition. The local clusters are compressed by increasing the viscosity coefficient in the cluster study.     

Orthogonal interaction of bernstein mode with ion-acoustic wave through plasma maser effect

Interaction of Bernstein mode wave with ion-acoustic turbulence is treated as the plasma maser effect. Ion-acoustic turbulence is considered as resonant mode, propagating orthogonal to the test Bernstein mode. The external magnetic field, in the direction of ion-acoustic turbulence, is playing key role in transferring energy in upconversion process from resonant low frequency wave to the high frequency wave through modulated electric field. It is shown that the direct coupling term and the associated reverse absorbtion effect do not contribute individually to the growth or damping to the Bernstein mode. Only the polarization coupling term is found to be effective in the energy upconversion process as the external magnetic field is providing momentum in the direction of propagation of Bernstein mode. The polarization coupling term is identified to be the dominant upconversion factor in the plasma maser effect.     

Enhancement of the Kondo effect through Rashba spin-orbit interactions

We study a one-orbital Anderson impurity in a two-dimensional electron bath with Rashba spin-orbit interactions in the Kondo regime. The spin SU(2) symmetry-breaking term couples the impurity to a two-band electron gas. A Schrieffer-Wolff transformation shows the existence of the Dzyaloshinsky-Moriya interaction away from the particle-hole symmetric impurity state. A renormalization group analysis reveals a two-channel Kondo model with ferro- and antiferromagnetic couplings. The parity-breaking Dzyaloshinsky-Moriya term renormalizes the antiferromagnetic Kondo coupling with an exponential enhancement of the Kondo temperature.     

The perfluoro effect on the molecular Rydberg states of bromo- and iodoethylene

In comparing the vacuum ultraviolet spectra of bromo- and iodoethylene with the spectra of their perfluoro analogs, it is noted that many of the absorptions are shifted in energy. Fluorine substitution has been found to stabilize the σ systems and increase the term values of (π, ns) Rydberg transitions, but to have little effect on π ionization potentials or p Rydberg term values. However, in these compounds, there are two (π, np) Rydberg series assigned, and the term values of one series associated with in-plane p Rydberg orbitals, showed a marked increase with fluorination. Additional substituent effects on halogen-π system interaction parameters have also been observed and are discussed.     

Electronic structure of three-dimensional topological insulators: thickness dependence and warping effect

We theoretically study the electronic structure of a three-dimensional topological insulator using a 3D lattice model with a warping term included. Thickness dependence of the electronic structure and the shape of constant-energy contour at different energy are both investigated in this model. We demonstrate that an energy gap opens in the surface state when the thickness is below six quintuple layers and disappears for thicker topological insulators. With the increasing of energy, the shape of constant-energy contour of the surface state band gradually evolves from a point at Dirac point to a circle with increasing volume, then to a hexagon, and finally to a hexagram. We clarify that the critical thickness of six quintuple is not modified by the warping term and the appearance of a hexagram is not influenced by the finite size effect. These phenomena agree well with recent angle-resolved photoemission spectroscopy experiments.     

Torque equations for spin and orbital angular momenta of radiation fields and Faraday effect

The spin angular momentum S of light has never been linked to the Faraday rotation of light traveling in an optically active medium possessing a rotational invariance of a crystal, because there was no helicity term associated with the phase shift in the previous torque equation for S. In order to relate the change in S with time to the Faraday rotation, therefore, we derived an exact torque equation for S. As a result, a magnetic helicity term appeared in a new torque equation for S, so that one-half of the phase shift derived from the helicity term was equivalent to the Faraday rotation angle. However, the orbital angular momentum L had no relation to the Faraday rotation. It was thus clarified that the change in S with time is related to the Faraday rotation angle of light traveling in an optically active medium, owing to the appearance of the helicity term without a rotational invariance around the optical axis. It was also demonstrated theoretically that the Faraday rotation is accompanied by a torque acting on the crystal so that the total angular momentum of light and matter is conserved.     

Anomalous Hall effect in noncommutative mechanics

The anomalous velocity term in the semiclassical model of a Bloch electron deviates the trajectory from the conventional one. When the Berry curvature (alias noncommutative parameter) is a monopole in momentum space, as found recently in some ferromagnetic semiconductors while observing the anomalous Hall effect, we get a transverse shift, similar to that in the optical Hall effect.     

Inelastic collisional effect on a dilute granular shock layer with a heated wall

The inelastic collisional effect on a shock layer of a dilute granular gas with a heated wall is numerically studied. To investigate the inelastic collisional effect via the gain term in the inelastic Boltzmann equation on the shock layer, an inelastic Bhatnagar-Gross-Krook (BGK) type equation, whose loss term is equivalent to that in the inelastic Boltzmann equation, is formulated on the basis of the kinetic theory of the granular gas. The inelastic BGK-type equation formulated for a hard-sphere particle is generalized to that for an inverse power law (IPL) molecule. Numerical results in a weakly inelastic regime confirm the nonequilirium contribution to the cooling rate, when the collision frequency depends on the particle velocity. The profile of the negative high-velocity tail of the distribution function in the generation regime of the shock wave obtained by the Direct Simulation Monte Carlo method is higher than that obtained by the proposed BGK-type equation when the collision frequency depends on the particle velocity because of the inelastic collisional effect via the gain term in the inelastic Boltzmann equation, which is not included in the proposed BGK-type equation.     

Fano effect in a T-shaped double quantum dot structure in the presence of Rashba spin-orbit coupling

The influence of Rashba spin-orbit coupling on the Fano lineshape of the conductance spectrum in a T-shaped double quantum dot structure is theoretically studied. By second-quantizing the electron Hamiltonian in this structure, it is found that the Rashba interaction brings about a spin-flip interdot hopping term. With the enhancement of the Rashba interaction, this term separates the two resonant peaks in the conductance spectrum from each other. More importantly, it causes the broadening of the narrow Fano peak, and the narrowing of the broader peak. Finally, the asymmetric Fano lineshape changes into a symmetric profile in the global conductance spectrum.