Transport of non-equilibrium quasiparticle excitations in superconducting aluminum

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

The electron transport of non-equilibrium quasiparticles injected into superconducting aluminum from a normal metal has been experimentally studied at ultralow temperatures. We studied hybrid nanostructures in the form of a T-shaped normal metal electrode (copper) – a dielectric tunnel layer (aluminum oxide) – a superconducting fork (aluminum), which can be considered as a solid-state analogues of a two-beam optical interferometer. At fixed bias voltages larger than the superconducting gap, a non-monotonic dependence of the tunnel current on perpendicular magnetic field is observed. The effect is interpreted as the presence of a coherent component of the quasiparticle current.

Full Text

Restricted Access

About the authors

A. S. Gursky

Higher School of Economics National Research University

Author for correspondence.
Email: karutyunov@hse.ru
Russian Federation, Moscow

D. L. Shapovalov

Kapitza Institute for Physical Problems of the Russian Academy of Sciences

Email: karutyunov@hse.ru
Russian Federation, Moscow

K. Yu. Arutyunov

Higher School of Economics National Research University; Kapitza Institute for Physical Problems of the Russian Academy of Sciences

Email: karutyunov@hse.ru
Russian Federation, Moscow; Moscow

References

  1. Камашев А.А., Большаков С.А., Мамин Р.Ф., Гарифуллин И.А. // Изв. РАН. Сер. физ. 2023. Т. 87. № 9. С. 1268; Kamashev A.A., Bolshakov S.A., Mamin R.F., Garifullin I.A. // Bull. Russ. Acad. Sci. Phys. 2023. V. 87. No. 9. P. 1308.
  2. Гайфуллин Р.Р., Деминов Р.Г., Кушнир В.Н. и др. // Изв. РАН. Сер. физ. 2023. Т. 87. № 4. С. 468; Gaifullin R.R., Deminov R.G., Kushnir V.N. et al. // Bull. Russ. Acad. Sci. Phys. 2023. V. 87. No. 4. P. 404.
  3. Tinkham M. Introduction to superconductivity. McGraw-Hill Inc., 1996.
  4. Clarke J. Nonequlibrium superconductivity, phonons, and Kapitza boundaries. New York: Plenum Press, 1981.
  5. Kopnin N. Theory of nonequilibrium superconductivity. New York: Oxford University Press, 2001.
  6. Tinkham M., Clarke J. // Phys. Rev. Lett. 1972. V. 28. No. 21. P. 1366.
  7. Clarke J. // Phys. Rev. Lett. 1972. V. 28. No. 21. P. 1363.
  8. Yagi R. // Superlattices and microstructures. 2003. V. 34. No. 3‒6. P. 263.
  9. Beckmann D., Weber H.B., v. Löhneysen H. // Phys. Rev. Lett. 2004. V. 93. Art. No. 197003.
  10. Russo S., Kroug M., Klapwijk T.M., Morpurgo A.F. // Phys. Rev. Lett. 2005. V. 95. Art. No. 027002.
  11. Cadden Zimansky P., Chandrasekhar V. // Phys. Rev. Lett. 2006. V. 97. Art. No. 237003.
  12. Arutyunov K.Yu., Auraneva H.–P., Vasenko A.S. // Phys. Rev. B. 2011. V. 83. Art. No. 104509.
  13. Arutyunov K.Yu., Chernyaev S.A., Karabassov T. et al. // J. Phys. Cond. Matter. 2018. V. 30. Art. No. 343001.
  14. Aharonov Y., Bohm D. // Phys. Rev. 1959. V. 115. P. 485.
  15. Zavyalov V., Chernyaev S., Shein K. et al. // J. Phys. Conf. Ser. 2018. V. 969. Art. No. 012086.
  16. Шарвин Д.Ю., Шарвин Ю.В. // Письма в ЖЭТФ. 1981. Т. 34. № 5. С. 101.
  17. Альтшулер Б.Л., Аронов А.Г., Спивак Б.З. // Письма в ЖЭТФ. 1981. Т. 33. № 2. С. 101.

Supplementary files

Supplementary Files
Action
1. JATS XML
Download
2. Fig. 1. Excitation spectrum for normal metal (a) and superconductor (b) at T = 0. Electron-like excitations are indicated in grey and hole-like excitations in red. In the absence of perturbation, all excited states are unfilled (both grey and red circles are hollow). In the equilibrium state in the superconductor (b), the Cooper pairs are at the origin: they have energy Ek = 0 and total momentum p = 0. At a finite temperature or an external influence leading to vaporisation of Cooper pairs, electron-like and hole-like perturbations appear, symmetrically filling both branches of the spectrum (c). When injecting a current of unpaired electrons into the superconductor, depending on the polarity of the applied bias, there may arise an asymmetric filling of the branches of the perturbation spectrum. For example, the excess of electron-like perturbations compared to hole-like perturbations (d)

Download (236KB)
Indexing metadata
3. Fig. 2. Schematic diagram of the NIS interferometer (a). Microphotograph of a typical nanostructure obtained by scanning electron microscopy (b)

Download (166KB)
Indexing metadata
4. Fig. 3. Voltammetric characteristic I(V) of the NIS interferometer at temperature T = 11 mK. The arrow indicates the direction of data recording. The inset shows a fragment of the VAC in the region of slot offsets V ~ 210 μV. The arrows indicate the values of voltage displacements V = Vbias = const, at which the dependences of the tunnelling current on the magnetic field I(V = Vbias, B) were further measured

Download (208KB)
Indexing metadata
5. Fig. 4. Examples of I(V = Vbias, B) dependences for the NIS interferometer measured at temperature T = 20 mK for several fixed values of the quasiparticle injection voltage Vbias = 208, 220, 230, and 239 μV. The arrows indicate the direction of sweep of the magnetic field B

Download (287KB)
Indexing metadata

Copyright (c) 2024 Russian Academy of Sciences