Edouard B. Sonin
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Edouard B. Sonin has a total of 2 co-authors. Here are the top co-authors by number of shared publications:
V. Braude
Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
2 shared publications- Pertti Juhani Hakonen
Aalto University
1 shared publication
Latest Publications
- Open Access
- 2 February 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 113 (6)
Theory of planar ballistic SNS junctions at T = 0
This Letter presents the theory of planar ballistic superconductor–normal metal–superconductor junctions at T = 0 for any normal layer thickness L taking into account phase gradients in superconducting leads. The current-phase relation was derived in the model of the steplike pairing potential analytically and is exact in the limit of large ratio of the Fermi energy to the superconducting gap. At small L (short junction) the obtained current-phase relation is essentially different from that in the previous theory neglecting phase gradients. It was confirmed by recent numerical calculations and was observed in the experiment on short InAs nanowire Josephson junctions. The analysis resolves the problem with the charge conservation law in the steplike pairing potential model.
- 2 February 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 113 (6)
Open AccessTheory of planar ballistic SNS junctions at T = 0
This Letter presents the theory of planar ballistic superconductor–normal metal–superconductor junctions at T = 0 for any normal layer thickness L taking into account phase gradients in superconducting leads. The current-phase relation was derived in the model of the steplike pairing potential analytically and is exact in the limit of large ratio of the Fermi energy to the superconducting gap. At small L (short junction) the obtained current-phase relation is essentially different from that in the previous theory neglecting phase gradients. It was confirmed by recent numerical calculations and was observed in the experiment on short InAs nanowire Josephson junctions. The analysis resolves the problem with the charge conservation law in the steplike pairing potential model.
- Open Access
- 19 January 2026
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 222 (1) , 29
The theory of planar ballistic SNS junctions
The paper presents the theory of planar ballistic SNS junctions with equal Fermi velocities and effective masses in all layers. The theory takes into account phase gradients in superconducting layers commonly ignored in the past. At $$T=0$$ , the current-phase relation was derived for any thickness L of the normal layer in the model of the steplike pairing potential model analytically. The obtained current-phase relation is essentially different from that in theory neglecting phase gradients, especially in the limit $$L\rightarrow 0$$ (short junction). The analysis resolves the problem with the charge conservation law in the steplike pairing potential model. The current-phase relation at temperatures exceeding the energy spacing between Andreev levels but less than the critical temperature was also calculated numerically. The current at these temperatures is temperature independent and decreases with growing L as $$1/L^4$$ . The previous theory predicted the current exponentially decreasing with growing T and L . Possible implications of the analysis for planar junctions with non-equal Fermi velocities and for non-planar junctions (narrow normal bridge between two bulk superconductors) are also discussed.- 19 January 2026
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 222 (1) , 29
Open AccessThe theory of planar ballistic SNS junctions
The paper presents the theory of planar ballistic SNS junctions with equal Fermi velocities and effective masses in all layers. The theory takes into account phase gradients in superconducting layers commonly ignored in the past. At $$T=0$$ , the current-phase relation was derived for any thickness L of the normal layer in the model of the steplike pairing potential model analytically. The obtained current-phase relation is essentially different from that in theory neglecting phase gradients, especially in the limit $$L\rightarrow 0$$ (short junction). The analysis resolves the problem with the charge conservation law in the steplike pairing potential model. The current-phase relation at temperatures exceeding the energy spacing between Andreev levels but less than the critical temperature was also calculated numerically. The current at these temperatures is temperature independent and decreases with growing L as $$1/L^4$$ . The previous theory predicted the current exponentially decreasing with growing T and L . Possible implications of the analysis for planar junctions with non-equal Fermi velocities and for non-planar junctions (narrow normal bridge between two bulk superconductors) are also discussed. - Open Access
The theory of planar ballistic SNS junctions
The paper presents the theory of planar ballistic SNS junctions with equal Fermi velocities and effective masses in all layers. The theory takes into account phase gradients in superconducting layers commonly ignored in the past. At $T=0$ the current-phase relation was derived for any thickness $L$ of the normal layer in the model of the steplike pairing potential model analytically. The obtained current-phase relation is essentially different from that in theory neglecting phase gradients, especially in the limit $L\to 0$ (short junction). The analysis resolves the problem with the charge conservation law in the steplike pairing potential model. The current-phase relation at temperatures exceeding the energy spacing between Andreev levels but less than the critical temperature was also calculated numerically. The current at these temperatures is temperature independent and decreases with growing $L$ as $1/L^4$. The previous theory predicted the current exponentially decreasing with growing $T$ and $L$. Possible implications of the analysis for planar junctions with non-equal Fermi velocities and for non-planar junctions (narrow normal bridge between two bulk superconductors) are also discussed.Open AccessThe theory of planar ballistic SNS junctions
The paper presents the theory of planar ballistic SNS junctions with equal Fermi velocities and effective masses in all layers. The theory takes into account phase gradients in superconducting layers commonly ignored in the past. At $T=0$ the current-phase relation was derived for any thickness $L$ of the normal layer in the model of the steplike pairing potential model analytically. The obtained current-phase relation is essentially different from that in theory neglecting phase gradients, especially in the limit $L\to 0$ (short junction). The analysis resolves the problem with the charge conservation law in the steplike pairing potential model. The current-phase relation at temperatures exceeding the energy spacing between Andreev levels but less than the critical temperature was also calculated numerically. The current at these temperatures is temperature independent and decreases with growing $L$ as $1/L^4$. The previous theory predicted the current exponentially decreasing with growing $T$ and $L$. Possible implications of the analysis for planar junctions with non-equal Fermi velocities and for non-planar junctions (narrow normal bridge between two bulk superconductors) are also discussed. - 29 October 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 110 (13)
Erratum: Ballistic SNS sandwich as a Josephson junction [Phys. Rev. B 104 , 094517 (2021)]
- 29 October 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 110 (13)
Erratum: Ballistic SNS sandwich as a Josephson junction [Phys. Rev. B 104 , 094517 (2021)]
- Open Access
- 4 June 2024
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 217 (1-2) , 24-53
Andreev reflection, Andreev states, and long ballistic SNS junction
The analysis in the present paper is based on the most known concept introduced by the brilliant physicist Alexander Andreev: Andreev bound states in a normal metal sandwiched between two superconductors. The paper presents results of direct calculations of ab initio expressions for the currents in a long ballistic SNS junction. The expressions are expanded in 1/L (L is the thickness of the normal layer). The main contribution $$\propto 1/L$$ to the current agrees with the results obtained in the past, but the analysis suggests a new physical picture of the charge transport through the junction free from the problem with the charge conservation law. The saw-tooth current-phase relation at $$T=0$$ directly follows from the Galilean invariance of the Bogolyubov–de Gennes equations proved in the paper. The proof is valid for any variation of the energy gap in space if the Andreev reflection is the only scattering process. The respective roles of the contributions of bound and continuum states to the current are clarified. They depend on the junction dimensionality.- 4 June 2024
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 217 (1-2) , 24-53
Open AccessAndreev reflection, Andreev states, and long ballistic SNS junction
The analysis in the present paper is based on the most known concept introduced by the brilliant physicist Alexander Andreev: Andreev bound states in a normal metal sandwiched between two superconductors. The paper presents results of direct calculations of ab initio expressions for the currents in a long ballistic SNS junction. The expressions are expanded in 1/L (L is the thickness of the normal layer). The main contribution $$\propto 1/L$$ to the current agrees with the results obtained in the past, but the analysis suggests a new physical picture of the charge transport through the junction free from the problem with the charge conservation law. The saw-tooth current-phase relation at $$T=0$$ directly follows from the Galilean invariance of the Bogolyubov–de Gennes equations proved in the paper. The proof is valid for any variation of the energy gap in space if the Andreev reflection is the only scattering process. The respective roles of the contributions of bound and continuum states to the current are clarified. They depend on the junction dimensionality. - 21 November 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 108 (17) , 176502
Reply to “Comment on ‘Ballistic SNS sandwich as a Josephson junction’ ”
This is the Reply to the Comment by E. Thuneberg refuting the paper by E. B. Sonin [ Phys. Rev. B 104, 094517 (2021)] as incorrect. The criticism is based on a misunderstanding of the goal and the approach of the paper and does not provide any reasonable argument that it is incorrect.
- 21 November 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 108 (17) , 176502
Reply to “Comment on ‘Ballistic SNS sandwich as a Josephson junction’ ”
This is the Reply to the Comment by E. Thuneberg refuting the paper by E. B. Sonin [ Phys. Rev. B 104, 094517 (2021)] as incorrect. The criticism is based on a misunderstanding of the goal and the approach of the paper and does not provide any reasonable argument that it is incorrect.
- Open Access
Joe Vinen and transverse force on vortex
The paper gives a glimpse on the problem of transverse force on a vortex, its proper determination in general and the role in the process of quantum vortex nucleation. Investigation of this problem is an essential part of the scientific heritage of Joe Vinen as an experimentalist and a theoretician.
Open AccessJoe Vinen and transverse force on vortex
The paper gives a glimpse on the problem of transverse force on a vortex, its proper determination in general and the role in the process of quantum vortex nucleation. Investigation of this problem is an essential part of the scientific heritage of Joe Vinen as an experimentalist and a theoretician.
- 24 May 2023
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 212 (5-6) , 306-320
Joe Vinen and the Transverse Force on Vortex
- 24 May 2023
- Published by Springer Nature in Journal of Low Temperature Physics
- Vol. 212 (5-6) , 306-320
Joe Vinen and the Transverse Force on Vortex
- 13 June 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 105 (21) , 219902
Erratum: Ballistic SNS sandwich as a Josephson junction [Phys. Rev. B 104 , 094517 (2021)]
DOI: https://doi.org/10.1103/PhysRevB.105.219902
- 13 June 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 105 (21) , 219902
Erratum: Ballistic SNS sandwich as a Josephson junction [Phys. Rev. B 104 , 094517 (2021)]
DOI: https://doi.org/10.1103/PhysRevB.105.219902
- 1 May 2022
- Published by AIP Publishing in Low Temperature Physics
- Vol. 48 (5) , 400-412
Quantum rotator and Josephson junction: Compact vs. extended phase and dissipative quantum phase transition
This paper reassesses the old dilemma “compact vs. extended phase” in the quantum theory of the rotator and the Josephson junction and the analogy of these two systems with a particle moving in a periodic potential. This dilemma is in fact the dilemma of whether the states with the phases φ and φ + 2π are distinguishable, or not. In the past it was widely accepted that in the Josephson junction these states are distinguishable, as in the case of a particle moving in a periodic potential. This paper argues that the states with the phases φ and φ + 2π are indistinguishable as in a pendulum (a particular example of the quantum rotator). However, this does not lead to revision of the conclusions of the conventional theory predicting the transition from the superconducting to the insulating state in the small Josephson junction.
- 1 May 2022
- Published by AIP Publishing in Low Temperature Physics
- Vol. 48 (5) , 400-412
Quantum rotator and Josephson junction: Compact vs. extended phase and dissipative quantum phase transition
This paper reassesses the old dilemma “compact vs. extended phase” in the quantum theory of the rotator and the Josephson junction and the analogy of these two systems with a particle moving in a periodic potential. This dilemma is in fact the dilemma of whether the states with the phases φ and φ + 2π are distinguishable, or not. In the past it was widely accepted that in the Josephson junction these states are distinguishable, as in the case of a particle moving in a periodic potential. This paper argues that the states with the phases φ and φ + 2π are indistinguishable as in a pendulum (a particular example of the quantum rotator). However, this does not lead to revision of the conclusions of the conventional theory predicting the transition from the superconducting to the insulating state in the small Josephson junction.