arXiv subjects

Yurii Ovchinnikov

Publications and source records attributed to Yurii Ovchinnikov.

4 recordsLinked to original sources

arXiv2014

Pair correlation and dynamic Jahn-Teller effect: high Tc in nanoclusters

Electronic states in metallic nanoclusters form energy shells and degree of their filling depends on the number of delocalized electrons. In the region close to half-filling the cluster geometry oscillates between the prolate and oblate configurations (dynamic Jahn-Teller effect). For large clusters this effect competes with pair correlation and, as a result, it is perfectly realistic to observe the transition to the superconducting state. For some clusters the value of the critical temperature is rather high, near 140K

cond-mat.supr-con↗

arXiv2013

Networks of Josephson junctions and their synchronization

One can demonstrate that a 1-D Josephson network containing junctions with different resistances can be synchronized at frequencies, which are multiples of 2eV, where V is the total d.c. voltage applied across the network. The appearance of such synchronization follows from the law of charge conservation and takes place if charge transfer is dominated by the Josephson channel. One can observe also a sub-harmonic structure. The result holds for cluster-based arrays as well as for general case of a tunneling network.

cond-mat.supr-con↗

arXiv2012

Cluster-based Superconducting Tunneling Networks

A 2D tunneling network consisting of nanoclusters placed on a surface is studied. It is shown that such a network is capable of transferring large supercurrent at high temperatures. For a realistic set of parameters the damping is quite small, and the smallness is due to strong renormalization of the capacitance of a cluster. The critical field also turns out to be lar

cond-mat.supr-con↗

arXiv2010

Josephson tunneling and nanosystems

Josephson tunneling between nanoclusters is analyzed. The discrete nature of the electronic energy spectra, including their shell ordering, is explicitly taken into account. The treatment considers the two distinct cases of resonant and non-resonant tunneling. It is demonstrated that the current density greatly exceeds the value discussed in the conventional theory. Nanoparticles are shown to be promising building blocks for nanomaterials-based tunneling networks.

cond-mat.supr-con↗