scholarly journals Long-range Josephson effect controlled by temperature gradient and circuit topology

2021 ◽  
Author(s):  
Mikhail S. Kalenkov ◽  
Andrei D. Zaikin
Keyword(s):  
Temperature Gradient ◽  
Long Range ◽  
Josephson Effect ◽  
Josephson Current ◽  
Hybrid Nanostructures ◽  
Proper Choice ◽  
Circuit Topology ◽  
System Geometry ◽  
Non Equilibrium

AbstractWe demonstrate that the supercurrent can be strongly enhanced in cross-like superconducting hybrid nanostructures (X-junctions) exposed to a temperature gradient. At temperatures T exceeding the Thouless energy of our X-junction, the Josephson current decays algebraically with increasing T and can be further enhanced by a proper choice of the circuit topology. At large values of the temperature gradient, the non-equilibrium contribution to the supercurrent may become as large as the equilibrium one at low T. We also predict a variety of transitions between 0- and $$\pi $$ π -junction states controlled by the temperature gradient as well as by the system geometry. Our predictions can be directly verified in modern experiments.

A Theoretical Study of the Temperature Gradient Effect on the Soret Coefficient in n-Pentane/n-Decane Mixtures Using Non-Equilibrium Molecular Dynamics

2020 ◽  
Vol 45 (4) ◽  
pp. 319-332
Author(s):  
Xiaoyu Chen ◽  
Ruquan Liang ◽  
Yong Wang ◽  
Ziqi Xia ◽  
Lichun Wu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Temperature Gradient ◽  
Thermal Gradient ◽  
Linear Response ◽  
Theoretical Study ◽  
Soret Coefficient ◽  
Thermal Gradients ◽  
Gradient Effect ◽  
Non Equilibrium Molecular Dynamics ◽  
Non Equilibrium

AbstractThe effect of the temperature gradient on the Soret coefficient in n-pentane/n-decane (n-C5/n-C10) mixtures was investigated using non-equilibrium molecular dynamics (NEMD) with the heat exchange (eHEX) algorithm. n-Pentane/n-decane mixtures with three different compositions (0.25, 0.5, and 0.75 mole fractions, respectively) and the TraPPE-UA force field were used in computing the Soret coefficient ({S_{T}}) at 300 K and 1 atm. Added/removed heat quantities (ΔQ) of 0.002, 0.004, 0.006, 0.008, and 0.01 kcal/mol were employed in eHEX processes in order to study the effect of different thermal gradients on the Soret coefficient. Moreover, a phenomenological description was applied to discuss the mechanism of this effect. Present results show that the Soret coefficient values firstly fluctuate violently and then become increasingly stable with increasing ΔQ (especially in the mixture with a mole fraction of 0.75), which means that ΔQ has a smaller effect on the Soret coefficient when the temperature gradient is higher than a certain thermal gradient. Thus, a high temperature gradient is recommended for calculating the Soret coefficient under the conditions that a linear response and constant phase are ensured in the system. In addition, the simulated Soret coefficient obtained at the highest ΔQ within three different compositions is in great agreement with experimental data.

Direct Determination of the Velocity of Vortices in High-Tc Superconductors by a Non-Equilibrium Method

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3288-3291
Author(s):  
I. Kirschner ◽  
R. Laiho ◽  
A. C. Bódi ◽  
E. Lähderanta ◽  
I. Vajda
Keyword(s):  
Magnetic Field ◽  
Temperature Gradient ◽  
Vortex Motion ◽  
Direct Determination ◽  
Field Investigation ◽  
High Tc Superconductors ◽  
High Tc ◽  
Pinning Centers ◽  
Non Equilibrium

As is shown, thermally assisted vortex motion can come into being in high-T c superconductors due to the applied temperature gradient. Its behavior strongly depends on the local and global microstructure of the samples, moreover on the temperature and magnetic field. Investigation of the density, size and intensity of the pinning centers of specimens leads to the conclusion that the higher homogeneity immediately weakens and the lower one strenghtens the pinning, thus the former promotes and the latter impedes the vortex motion. The non-equilibrium experimental technique together with a.c. susceptibility measurements render possible the direct determination of the velocity of vortices. Depending on the actual microstructural state of samples it has the values between 6 × 10-2 mm/s and 18 × 10-2 mm/s in the case of Y-Ba-Cu-O specimens investigated.

scholarly journals Josephson effect in junctions of conventional and topological superconductors

2018 ◽  
Vol 9 ◽  
pp. 1659-1676 ◽  
Author(s):  
Alex Zazunov ◽  
Albert Iks ◽  
Miguel Alvarado ◽  
Alfredo Levy Yeyati ◽  
Reinhold Egger
Keyword(s):  
Bound States ◽  
Josephson Effect ◽  
Mean Field ◽  
Josephson Current ◽  
Field Analysis ◽  
Current Phase ◽  
Topological Superconductor ◽  
Topological Superconductors ◽  
Spin Singlet ◽  
Hybrid Devices

We present a theoretical analysis of the equilibrium Josephson current-phase relation in hybrid devices made of conventional s-wave spin-singlet superconductors (S) and topological superconductor (TS) wires featuring Majorana end states. Using Green’s function techniques, the topological superconductor is alternatively described by the low-energy continuum limit of a Kitaev chain or by a more microscopic spinful nanowire model. We show that for the simplest S–TS tunnel junction, only the s-wave pairing correlations in a spinful TS nanowire model can generate a Josephson effect. The critical current is much smaller in the topological regime and exhibits a kink-like dependence on the Zeeman field along the wire. When a correlated quantum dot (QD) in the magnetic regime is present in the junction region, however, the Josephson current becomes finite also in the deep topological phase as shown for the cotunneling regime and by a mean-field analysis. Remarkably, we find that the S–QD–TS setup can support φ0-junction behavior, where a finite supercurrent flows at vanishing phase difference. Finally, we also address a multi-terminal S–TS–S geometry, where the TS wire acts as tunable parity switch on the Andreev bound states in a superconducting atomic contact.

scholarly journals Long-range triplet Josephson current driven by the bias voltage

2014 ◽  
Vol 378 (30-31) ◽  
pp. 2263-2269
Author(s):  
Hao Meng ◽  
Xiuqiang Wu ◽  
Feng Mei
Keyword(s):  
Long Range ◽  
Bias Voltage ◽  
Josephson Current

Non-Equilibrium Critical Dynamics of Ferromagnets with Long Range Correlated Defects

2012 ◽  
Vol 190 ◽  
pp. 31-34
Author(s):  
Dmitry N. Kulikov ◽  
Pavel V. Prudnikov
Keyword(s):  
Critical Exponent ◽  
Long Range ◽  
Critical Behavior ◽  
Disordered Systems ◽  
Asymptotic Series ◽  
Three Dimensional ◽  
Time Regime ◽  
Short Time ◽  
Short Time Evolution ◽  
Non Equilibrium

The simultaneous effect of non-equilibrium initial states and correlation betweendefects of the structure on the evolution of anisotropic disordered systems at the critical pointwas analyzed. The field theory description of the non-equilibrium critical behavior of three-dimensional disordered systems with the long-range correlated defects was given and the dy-namical critical exponent of the short-time evolution was calculated in the two-loop approxima-tion without the use of the "-expansion. The values of the dynamical critical exponent obtainedby using various methods for summing asymptotic series were compared with the results ofthe computer simulation of the non-equilibrium critical behavior of the three-dimensional dis-ordered Ising model in the short-time regime.

scholarly journals Kinetic theory for non-equilibrium stationary states in long-range interacting systems

2012 ◽  
Vol 2012 (01) ◽  
pp. L01002 ◽  
Author(s):  
Cesare Nardini ◽  
Shamik Gupta ◽  
Stefano Ruffo ◽  
Thierry Dauxois ◽  
Freddy Bouchet
Keyword(s):  
Kinetic Theory ◽  
Long Range ◽  
Stationary States ◽  
Interacting Systems ◽  
Non Equilibrium
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