arXiv subjects

A. Tsvetkov

Publications and source records attributed to A. Tsvetkov.

5 recordsLinked to original sources

arXiv2007

Reflection symmetry instability at high spins in 162,164Yb

A shape evolution of 162,164Yb in yrast states is traced using the self-consistent Skyrme Hartree-Fock calculations. We found that nonaxial octupole deformations (in particular, Y_{31} term) become favorable at large rotational frequencies (> 0.4 MeV) in 162Yb, while in 164Yb a nonaxial quadrupole shape is dominant at fast rotation. The cranked Nilsson model and random phase approximation are used to understand the dynamics of octupole correlations in both nuclei. We demonstrate that the disappearance of one of the octupole vibrational modes in the rotating frame gives rise to the nonaxial octupole deformations in 162Yb, while the octupole modes are nonzero in 164Yb.

nucl-th↗

arXiv2001

Signature inversion in axially deformed $^{160,162}$Tm

The microscopic analysis of experimental data in $^{160,162}$Tm is presented within the two-quasiparticle-phonon model. The model includes the interaction between odd quasiparticles and their coupling with core vibrations. The coupling explains naturally the attenuation of the Coriolis interaction in rotating odd-odd nuclei. It is shown that the competition between the Coriolis and neutron-proton interactions is responsible for the signature inversion phenomenon.

nucl-th↗

arXiv2000

Octupole deformations in actinides at high spins within the cranking Skyrme-Hartree-Fock approach

The cranked Skyrme III effective Hamiltonian is applied for the analysis of the rotational dependence of the quadrupole and octupole moments in Ra, Th, and U isotopes. A comparison of the intrinsic electric dipole moments calculated in the model with available experimental and theoretical values is presented. It is found that the non-axial octupole deformation $Y_{32}$ becomes favorable at high spins for the actinide nuclei.

nucl-th↗

arXiv2000

C-axis optical properties of high Tc cuprates

A review is given of the experimental status of the interlayer coupling energy in the cuprates. A second c-axis plasmon is identified in the double layer compound Y123 for various dopings. The anomalous transport properties along the c-direction and in the planar directions are compared to model calculations based on strongly anisotropic scattering. An excellent description of the optical data at optimal doping is obtained if an anomalously large anisotropy of the scattering rate between cold spots and hot spots is assumed. This raises questions as to the physical meaning of these parameters.

cond-mat.supr-con↗

arXiv1996

Transverse optical plasmons in layered superconductors

We discuss the possible existance of transverse optical plasma modes in superlattices consisting of Josephson coupled superconducting layers. These modes appear as resonances in the current-current correlation function, as opposed to the usual plasmons which are poles in the density-density channel. We consider both bilayer superlattices, and single layer lattices with a spread of interlayer Josephson couplings. We show that our model is in quantitative agreement with the recent experimental observation by a number of groups of a peak at the Josephson plasma frequency in the optical conductivity of La$_{1.85}$Sr$_{0.15}$CuO$_4$

cond-mat↗