UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 17:58
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Conference: Bucharest University Faculty of Physics 2017 Meeting


Section: Physics and Technology of Renewable and Alternative Energy Sources


Title:
Generation of collective states in Josephson heterostructures with large coupling and dissipation parameters.


Authors:
Alexei ZUBAREV(1,2), Marina CUZMINSCHI(1), Ioan STAMATIN(1), Yury M. SHUKRINOV(3,4)


*
Affiliation:
1) 3)University of Bucharest, Faculty of Physics, MG-11, 405 Atomistilor Street, Bucharest-Magurele, Romania

2) INFLPR, 409 Atomistilor Street PO Box MG-36, 077125 Magurele, Bucharest

Romania

3) BLTP, Joint Institute for Nuclear Research, Dubna, Russia

4) Dubna State University, Dubna, Russia


E-mail
alxzubarev@gmail.com


Keywords:
Josephson Junctions, nano-structures, collective states


Abstract:
One of the way of manipulating of Josephson nano-structures is a varying its dissipation parameter. The detailed study of the c-axis charge travelling wave in a coupled system of Josephson junctions with a small dissipation parameter is presented in Ref. [1]. In our work we simulate the Josephson systems with different dissipation parameter (from 0.2 to 1.3), coupling parameter (from 0 to 1.3), and number of junctions (from 1 to 20). We observed a reduction in McCumber hysteresis with increase of dissipation and coupling parameters and also with number of junctions in the stack. For coupled systems we have found two distinct cases for McCumber hysteresis, for stacks with odd and even number of junctions, shrinkage being more pronounced in the case of odd stacks. We observed a second hysteresis zone on IV-characteristic at some values of dissipation and coupling parameters related to the creation of travelling longitudinal plasma wave. Results of temporal dependence of charge oscillations and fast Fourier transformation are presented. The second hysteresis zone is increased with increasing of coupling parameter. In the image attached are presented IV-characteristics of 10 coupled Josephson junctions, dissipation of 0.8 and coupling parameters of 0 and 1. Can be observed creation of second hysteresis for coupling parameter of 1, and a significant reduction in McCumber hysteresis.


References:

[1] Shukrinov, Yu M., and M. Hamdipour. "The c-axis charge travelling wave in a coupled system of Josephson junctions." JETP letters 95.6 (2012): 307-313.

Acknowledgement:
This work was partially supported by the Romanian Ministry of National Education by the contract PN 16 47 0101 with UEFISCDI and project 2016 / 25.of JINR-Romania collaboration.