Abstract
A novel self-textured nanofilament technique based on the resistive-switching effect in nano-scale transition-metal oxide films has been developed. While traditional tunneling and point-contact approaches to the electron–boson interaction spectroscopy in a strong-coupled superconductor are realized on different samples, the novel method allows one to get related data on the same device. Conductance traces of S/I/Pt junctions with two superconductors of interest (S = Nb and MgB2), a platinum counter-electrode and a double-oxide interlayer (I = Al2O3/TiO2) with a controllable interface transparency reveal superconducting-gap and phonon-induced features which disappear above the superconducting-to-normal state transition. In both cases, we have observed BCS gap features with comparatively strong broadening. In MgB2-based samples, nonlinearities in differential conductance-vs-voltage characteristics far above the energy gap were detected in two modes, a point-contact regime without any significant barrier at the superconductor/Pt interface and the tunneling one. In Nb-based junctions we have succeeded to realize only the first regime. The observed features arise at energies corresponding to maximums in the phonon density of states of niobium and magnesium diboride. Their amplitude and general shape agree with theoretical predictions of the electron–phonon coupling effect in the superconductors studied. We argue that the proposed nanoscale methodology provides a simple and promising way for studying an interaction responsible for Cooper pairing in superconducting materials.
This is a preview of subscription content,
to check access.





References
Baltz V, Naylor AD, Seemann KM, Elder W, Sheen S, Westerholt K, Zabel H, Burnell G, Marrows CH, Hickey BJ (2009) Conductance features in point contact Andreev reflection spectra. J Phys Condens Matter 21:095701–1–095701-8
Belogolovskii M (2009) Interface resistive switching effects in bulk manganites. Cent Eur J Phys 7:304–309
Blonder GE, Tinkham M, Klapwijk TM (1982) Transition from metallic to tunneling regimes in superconducting microconstrictions: excess current, charge imbalance, and supercurrent conversion. Phys Rev B 25(7):4515
Brinkman A, Golubov AA, Rogalla H, Dolgov OV, Kortus J, Kong Y, Jepsen O, Andersen OK (2002) Multiband model for tunneling in MgB2 junctions. Phys Rev B 65:180517–1–180517-4
Chen K, Dai W, Zhuang CG, Li Q, Carabello S, Lambert JG, Mlack JT, Ramos RC, Xi XX (2012) Momentum-dependent multiple gaps in magnesium diboride probed by electron tunnelling spectroscopy. Nat Commun 3:619-1–619-5
Daghero D, Gonnelli RS (2010) Probing multiband superconductivity by point-contact spectroscopy. Supercond Sci Technol 23:043001–1–043001-37
Daghero D, Tortello M, Ummarino GA, Gonnelli RS (2011) Directional point-contact Andreev-reflection spectroscopy of Fe-based superconductors: Fermi surface topology, gap symmetry, and electron–boson interaction. Rep Prog Phys 74:124509–1–124509-27
Dolgov OV, Gonnelli RS, Ummarino GA, Golubov AA, Shulga SV, Kortus J (2003) Extraction of the electron–phonon interaction from tunneling data in the multigap superconductor MgB2. Phys Rev B 68:132503–1–132503-4
Dvoranová M, Plecenik T, Moško M, Vidiš M, Gregor M, Roch T, Grančič B, Satrapinskyy L, Kúš P, Plecenik A (2018) Point contact spectroscopy of superconductors via nanometer scale point contacts formed by resistive switching. AIP Adv 8:125217-1–125217-18
Dynes RC, Narayanamurti V, Garno JP (1978) Direct measurement of quasiparticle-lifetime broadening in a strong-coupled superconductor. Phys Rev Lett 41:1509–1512
Gregor M, Sobota R, Plecenik T, Roch T, Satrapinskyy L, Kacmarcik J, Girman V, Svec P, Kus P, Plecenik A (2018) Enhancement of superconducting properties of MgB2 thin films by using oxygen annealing atmosphere. Appl Surf Sci 461:124–132
Herman F, Hlubina R (2016) Microscopic interpretation of the Dynes formula for the tunneling density of states. Phys Rev B 94:144508-1–144508-8
Hoskins BD, Adam GC, Strelcov E, Zhitenev N, Kolmakov A, Strukov DB, McClelland JJ (2017) Stateful characterization of resistive switching TiO2 with electron beam induced currents. Nat Commun 8:1972-1–1972-9
Hwang I, Lee K, Jin H, Choi S, Jung E, Park BH, Lee S (2015) A new simple method for point contact Andreev reflection. Nanoscale 7:8531–8535
Kashiwaya S, Tanaka Y, Koyanagi M, Kajimura K (1996) Theory for tunneling spectroscopy of anisotropic superconductors. Phys Rev B 53:2667–2676
Khotkevich AV, Yanson IK (1995) Atlas of point contact spectra of electron–phonon interactions in metals. Springer, Berlin, p 168
Knorr K, Leslie JD (1973) Ellipsometrical determination of barrier thicknesses of metal-insulator-metal tunnel junctions. Solid State Commun 12:615–619
Koza JA, Bohannan EW, Switzer JA (2013) Superconducting filaments formed during nonvolatile resistance switching in electrodeposited δ-Bi(2)O(3). ACS Nano 7:9940–9946
Lacquaniti V, Andreone D, De Leo N, Fretto M, Sosso A, Belogolovskii M (2009) Engineering overdamped niobium-based Josephson junctions for operation above 4.2 K. IEEE Trans Appl Supercond 19:234–237
McMillan WL (1968) Tunneling model of the superconducting proximity effect. Phys Rev 175:537–542
Miller TL, Zhang W, Ma J, Eisaki H, Moore JE, Lanzara A (2018) Interplay of superconductivity and bosonic coupling in the peak-dip-hump structure of Bi2Sr2CaCu2O8+δ. Phys Rev B 97:134517–1–134517-7
Naidyuk YUG, Yanson IK (2005) Point-contact spectroscopy. Springer, New York, p 297
Norman MR, Randeria M, Ding H, Campuzano JC (1998) Phenomenology of the low-energy spectral function in high-Tc superconductors. Rev B 57:R11093–R11096
Robinson B, Geballe TH, Rowell JM (1976) Tunneling study of niobium using aluminum–aluminum oxide niobium junctions. In: Douglass DH (ed) Superconductivity in d- and f-band metals. Plenum Press, New York, pp 381–386
Roch T, Gregor M, Švec P Jr, Plecenik T, Satrapinskyy L, Čaplovičová M, Bystrický R, Kúš P, Plecenik A (2018) Structure of superconducting MgB2 thin films prepared by vacuum evaporation and ex situ annealing in Ar and O2 atmospheres. Appl Surf Sci 461:233–241
Schrieffer JR (1964) Theory of superconductivity. Benjamin, New York, p 282
Shaternik V, Shapovalov A, Belogolovskii M, Suvorov O, Döring S, Schmidt S, Seidel P (2014) Transition from Coulomb blockade to resonant transmission regime in superconducting tunnel junctions with W-doped Si barriers. Mater Res Express 1:026001-1–026001-10
Takasaki T, Ekino T, Gabovich AM, Sugimoto A, Yamanaka S, Akimitsu J (2012) Tunneling spectroscopy of novel layered superconductors: MgB2, Li0.48(THF)XHfNCl and related substances. In: Romanovskií VR (ed) Superconductivity: theory, materials and applications. Nova Science Publ, Hauppauge, pp 1–110
Tsindlekht MI, Genkin VM, Leviev GI, Felner I, Yuli O, Asulin I, Millo O, Belogolovskii MA, Shitsevalova NYu (2008) Linear and nonlinear low-frequency electrodynamics of surface superconducting states in an yttrium hexaboride single crystal. Phys Rev B 78:024522–1–024522-11
Wolf EL (2012) Principles of electron tunneling spectroscopy, 2nd edn. Oxford University Press, New York, p 616
Wolf EL, Zasadzinski J, Osmun JW (1980) Proximity electron tunneling spectroscopy I. Experiments on Nb. J Low Temp Phys 40:19–50
Yang JJ, Miao F, Pickett MD, Ohlberg DAA, Stewart DR, Lau CN, Williams RS (2009) The mechanism of electroforming of metal oxide memristive switches. Nanotechnology 20:215201–1–215201-9
Yanson IK, Bobrov NL, Rybal’chenko LF, Fisun VV (1983) Spectroscopy of phonons in dirty superconducting contacts. Sov J Low Temp Phys 9:596–603
Zhu XJ, Shang J, Li RW (2012) Resistive switching effects in oxide sandwiched structures. Front Mater Sci 6:183–206
Acknowledgements
M. Belogolovskii is deeply grateful to the Slovak Academic Information Agency for the support of his stay at the Comenius University in Bratislava. This work was supported by the Slovak Research and Development Agency under Contract No. APVV-16-0315. It is also a result of the project implementation: ITMS 26240220027 and 26210120010 supported by the Research & Development Operational Program funded by the ERDF. The study was partly carried out within the Fundamental Research Programme funded by the Ministry of Education and Science of Ukraine, Project No. 0117U002360.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Zhitlukhina, E., Dvoranová, M., Plecenik, T. et al. Electron–boson coupling in superconductors studied by a self-formed nanofilament device. Appl Nanosci 10, 2617–2625 (2020). https://doi.org/10.1007/s13204-019-01082-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13204-019-01082-6