arXiv subjects

Leonid A. Openov

Publications and source records attributed to Leonid A. Openov.

4 recordsLinked to original sources

arXiv2004

Effect of nonmagnetic and magnetic impurities on the specific heat jump in anisotropic superconductors

The specific-heat jump $ΔC$ at a critical temperature $T_c$ in an anisotropic superconductor containing both potential and spin-flip scatterers is calculated within a weak-coupling mean-field approximation. It is shown that the presence of even a small amount of spin-flip scatterers in the sample leads to a drastic change in the dependence of $ΔC$ on $T_c$ in a disordered $(d+s)$-wave or a strongly anisotropic s-wave superconductor. The implications for experimental tests for the presence of an s-wave admixture in the superconducting order parameter of high-$T_c$ superconductors are discussed.

cond-mat.supr-con↗

arXiv1999

Resonant electron transfer between quantum dots

An interaction of electromagnetic field with a nanostructure composed of two quantum dots is studied theoretically. An effect of a resonant electron transfer between the localized low-lying states of quantum dots is predicted. A necessary condition for such an effect is the existence of an excited bound state whose energy lies close to the top of the barrier separating the quantum dots. This effect may be used to realize the reversible quantum logic gate NOT if the superposition of electron states in different quantum dots is viewed as the superposition of bits 0 and 1.

cond-mat.mes-hall↗

arXiv1998

Prismane C_8: A New Form of Carbon?

Our numerical calculations on small carbon clusters point to the existence of a metastable three-dimensional eight-atom cluster C$_8$ which has a shape of a six-atom triangular prism with two excess atoms above and below its bases. We gave this cluster the name "prismane". The binding energy of the prismane equals to 5.1 eV/atom, i.e., is 0.45 eV/atom lower than the binding energy of the stable one-dimensional eight-atom cluster and 2.3 eV/atom lower than the binding energy of the bulk graphite or diamond. Molecular dynamics simulations give evidence for a rather high stability of the prismane, the activation energy for a prismane decay being about 0.8 eV. The prismane lifetime increases rapidly as the temperature decreases indicating a possibility of experimental observation of this cluster.

physics.atm-clus↗

arXiv1997

Combined effect of nonmagnetic and magnetic scatterers on critical temperatures of superconductors with different gap anisotropy

The combined effect of nonmagnetic and magnetic defects and impurities on critical temperatures of superconductors with different gap anisotropy is studied theoretically within the weak coupling limit of the BCS model. An expression is derived which relates the critical temperature to relaxation rates of charge carriers by nonmagnetic and magnetic scatterers, as well as to the coefficient of anisotropy of the superconducting order parameter on the Fermi surface. Particular cases of d-wave, (s+d)-wave, and anisotropic s-wave superconductors are briefly discussed.

cond-mat.supr-con↗