Igor Batov
@issp.ac.ru
Laboratory of Superconductivity
Institute of Solid State Physics, Russian Academy of Sciences
09/1992 - 07/2000: Research Scientist, Institute of Solid State Physics, Russian Academy of Sciences.
07/2000 - 11/2003: Senior Research Scientist, Institute of Solid State Physics, Russian Academy of Sciences;
04/2001 - 06/2004: Research Scientist, Institute of Thin Films and Interfaces, ISG-1,Research Centre Juelich, Germany
09/2004 - 11/2005: Research Scientist, Institute of Physics, Abt. III, University of Erlangen-Nuernberg, Germany;
02/2006 - present, Senior Research Scientist, Institute of Solid State Physics, Russian Academy of Sciences
EDUCATION
Moscow Institute of Physics and Technology (State University); Post-graduate school at the Institute of Solid State Physics RAS.
Ph.D. in Physics, Institute of Solid State Physics RAS
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics
Scopus Publications
Scopus Publications
I. S. Lakunov, S. V. Egorov, E. D. Mukhanova, I. E. Batov, T. E. Golikova, and V. V. Ryazanov
Pleiades Publishing Ltd
T E Golikova, M J Wolf, D Beckmann, G A Penzyakov, I E Batov, I V Bobkova, A M Bobkov, and V V Ryazanov
IOP Publishing
A nonmonotonic dependence of the critical Josephson supercurrent on the injection current through a normal metal/ferromagnet weak link from a single domain ferromagnetic strip has been observed experimentally in nanofabricated planar crosslike S-N/F-S Josephson structures. This behavior is explained by 0–π and π–0 transitions, which can be caused by the suppression and Zeeman splitting of the induced superconductivity due to interaction between N and F layers, and the injection of spin-polarized current into the weak link. A model considering both effects has been developed. It shows the qualitative agreement between the experimental results and the theoretical model in terms of spectral supercurrent-carrying density of states of S-N/F-S structures and the spin-dependent double-step nonequilibrium quasiparticle distribution.
L. V. Ginzburg, I. E. Batov, V. V. Bol’ginov, S. V. Egorov, V. I. Chichkov, A. E. Shchegolev, N. V. Klenov, I. I. Soloviev, S. V. Bakurskiy, and M. Yu. Kupriyanov
Pleiades Publishing Ltd
A V Bubis, A O Denisov, S U Piatrusha, I E Batov, V S Khrapai, J Becker, J Treu, D Ruhstorfer, and G Koblmüller
IOP Publishing
We investigate the proximity effect in InAs nanowire (NW) junctions with superconducting contacts made of Al. The carrier density in InAs is tuned by means of the back gate voltage Vg. At high positive Vg the devices feature transport signatures characteristic of diffusive junctions with highly transparent interfaces—sizable excess current, re-entrant resistance effect and proximity gap values ( Δ N ) close to the Al gap ( Δ 0 ). At decreasing Vg, we observe a reduction of the proximity gap down to Δ N ≈ Δ 0 / 2 at NW conductances ∼ 2 e 2 h − 1 , which is interpreted in terms of carrier density dependent reduction of the Al/InAs interface transparency. We demonstrate that the experimental behavior of Δ N is closely reproduced by a model with rectangular potential barrier at the Al/InAs interface.
C. Weyrich, T. Merzenich, J. Kampmeier, I. E. Batov, G. Mussler, J. Schubert, D. Grützmacher, and Th. Schäpers
AIP Publishing
We report on the Shubnikov–de Haas oscillations in the longitudinal resistance of thin films of three-dimensional topological insulator Sb2Te3 grown by means of molecular beam epitaxy. The oscillations persist up to the temperatures of 30 K, and the measurements at various tilt angles reveal that they originate from a two-dimensional system. Using a top gate, we further study the change of oscillation amplitude and frequency, which in combination with the standard Hall measurements suggest the origin of oscillations to be at the interface between the film and the Si substrate.
C Weyrich, M Drögeler, J Kampmeier, M Eschbach, G Mussler, T Merzenich, T Stoica, I E Batov, J Schubert, L Plucinski,et al.
IOP Publishing
Ternary (Bi1−xSbx)2Te3 films with an Sb content between 0 and 100% were deposited on a Si(1 1 1) substrate by means of molecular beam epitaxy. X-ray diffraction measurements confirm single crystal growth in all cases. The Sb content is determined by x-ray photoelectron spectroscopy. Consistent values of the Sb content are obtained from Raman spectroscopy. Scanning Raman spectroscopy reveals that the (Bi1−xSbx)2Te3 layers with an intermediate Sb content show spatial composition inhomogeneities. The observed spectra broadening in angular-resolved photoemission spectroscopy (ARPES) is also attributed to this phenomena. Upon increasing the Sb content from x = 0 to 1 the ARPES measurements show a shift of the Fermi level from the conduction band to the valence band. This shift is also confirmed by corresponding magnetotransport measurements where the conductance changes from n- to p-type. In this transition region, an increase of the resistivity is found, indicating a location of the Fermi level within the band gap region. More detailed measurements in the transition region reveals that the transport takes place in two independent channels. By means of a gate electrode the transport can be changed from n- to p-type, thus allowing a tuning of the Fermi level within the topologically protected surface states.
A. V. Burmistrova, I. A. Devyatov, and I. E. Batov
IOP Publishing
We present a microscopic theory of the superconducting proximity effect in a semiconducting thin film with a spin-orbit interaction in an external magnetic field. We demonstrate that an effective 1D Hamiltonian which describes induced superconductivity in NSO in contact with a usual s-wave superconductor possesses not only a spin-singlet induced superconducting order parameter term, as commonly adopted, but also a spin triplet order parameter term. Using this new effective Hamiltonian we confirm previous results for a normal current across contacts of NSO with a normal metal and for a Josephson current with the same NSO with induced superconductivity, obtained previously in the framework of the phenomenological Hamiltonian without spin-triplet terms. However, a calculated current-phase relation across the transparent contact between NSO with induced superconductivity in magnetic field and a usual s-wave superconductor differs significantly from previous results. We suggest the experiment which can confirm our theoretical predictions.
H. Y. Günel, N. Borgwardt, I. E. Batov, H. Hardtdegen, K. Sladek, G. Panaitov, D. Grützmacher, and Th. Schäpers
American Chemical Society (ACS)
We report on the fabrication and characterization of symmetric nanowire-based Josephson junctions, that is, Al- and Nb-based junctions, and asymmetric junctions employing superconducting Al and Nb. In the symmetric junctions, a clear and pronounced Josephson supercurrent is observed. These samples also show clear signatures of subharmonic gap structures. At zero magnetic field, a Josephson coupling is found for the asymmetric Al/InAs-nanowire/Nb junctions as well. By applying a magnetic field above the critical field of Al or by raising the temperature above the critical temperature of Al the junction can be switched to an effective single-interface superconductor/nanowire structure. In this regime, a pronounced zero-bias conductance peak due to reflectionless tunneling has been observed.
T. E. Golikova, M. J. Wolf, D. Beckmann, I. E. Batov, I. V. Bobkova, A. M. Bobkov, and V. V. Ryazanov
American Physical Society (APS)
Nonlocal supercurrent was observed in mesoscopic planar SNS Josephson junction with additional normal metal electrodes when nonequilibrium quasiparticles were injected from the normal metal electrode in one of the superconducting banks of the Josephson junction in the absence of net transport current through the junction. We claim that the effect observed is due to a supercurrent counterflow appearing to compensate the quasiparticle flow in the SNS weak link. We have measured SNS junction response for different distances from the quasiparticle injector to the SNS junction at temperatures far below the superconducting transition temperature. The charge-imbalance relaxation length was estimated by using modified Kadin, Smith and Skocpol scheme in the case of planar geometry. The model developed allows to describe the interplay of the charge imbalance and Josephson effects in the nanoscale proximity system in detail.
T. E. Golikova, F. Hübler, D. Beckmann, N. V. Klenov, S. V. Bakurskiy, M. Yu. Kupriyanov, I. E. Batov, and V. V. Ryazanov
Pleiades Publishing Ltd
H. Yusuf Günel, Igor E. Batov, Hilde Hardtdegen, Kamil Sladek, Andreas Winden, Gregor Panaitov, Detlev Grützmacher, and Thomas Schäpers
AIP
We used InAs nanowires with two different charge carrier concentration to fabricate Josephson junctions with superconducting Nb electrodes. For highly doped nanowire junctions a supercurrent is observed up to T ∼ 5 K, for low doped nanowire junctions we were able to tune the Josephson current by a back gate voltage. Owing to the transparent interface between Nb and InAs nanowires subharmonic gap structures due to multiple Andreev reflection have been observed. Furthermore, the effect of magnetic field on the Josephson current was investigated and a monotonous decrease of Josephson current was found. The observed behavior has been compared with a theoretical model.
T. E. Golikova, F. Hübler, D. Beckmann, I. E. Batov, T. Yu. Karminskaya, M. Yu. Kupriyanov, A. A. Golubov, and V. V. Ryazanov
American Physical Society (APS)
We have investigated the differential resistance of hybrid planar Al-(Cu/Fe)-Al submicron bridges at low temperatures and in weak magnetic fields. The structure consists of a Cu/Fe bilayer forming a bridge between two superconducting Al electrodes. In the superconducting state of Al electrodes, we have observed a double-peak peculiarity in differential resistance of the S-(N/F)-S structures at a bias voltage corresponding to the minigap. We claim that this effect (the splitting of the minigap) is due to an electron spin polarization in the normal metal which is induced by the ferromagnet. We have demonstrated that the double-peak peculiarity is converted to a single peak at a coercive applied field corresponding to zero magnetization of the Fe layer
H. Y. Günel, I. E. Batov, H. Hardtdegen, K. Sladek, A. Winden, K. Weis, G. Panaitov, D. Grützmacher, and Th. Schäpers
AIP Publishing
We report on the fabrication and measurements of planar mesoscopic Josephson junctions formed by InAs nanowires coupled to superconducting Nb terminals. The use of Si-doped InAs-nanowires with different bulk carrier concentrations allowed to tune the properties of the junctions. We have studied the junction characteristics as a function of temperature, gate voltage, and magnetic field. For junctions with high doping concentrations in the nanowire, Josephson supercurrent values up to 100 nA are found. Owing to the use of Nb as superconductor, the Josephson coupling persists at temperatures up to 4 K. In all junctions, the critical current monotonously decreased with the magnetic field, which can be explained by a recently developed theoretical model for the proximity effect in ultra-small Josephson junctions. For the low-doped Josephson junctions, a control of the critical current by varying the gate voltage has been demonstrated. We have studied conductance fluctuations in nanowires coupled to superconducting and normal metal terminals. The conductance fluctuation amplitude is found to be about 6 times larger in superconducting contacted nanowires. The enhancement of the conductance fluctuations is attributed to phase-coherent Andreev reflection as well as to the large number of phase-coherent channels due to the large superconducting gap of the Nb electrodes.
G. V. Strukov, G. K. Strukova, I. E. Batov, M. K. Sakharov, E. A. Kudrenko, and A. A. Mazilkin
American Scientific Publishers
R. Frielinghaus, I. E. Batov, M. Weides, H. Kohlstedt, R. Calarco, and Th. Schäpers
AIP Publishing
We experimentally studied the Josephson supercurrent in Nb/InN-nanowire/Nb junctions. Large critical currents up to 5.7 μA have been achieved, which proves the good coupling of the nanowire to the superconductor. The effect of a magnetic field perpendicular to the plane of the Josephson junction on the critical current has been studied. The observed monotonous decrease in the critical current with magnetic field is explained by the magnetic pair-breaking effect in planar Josephson junctions of ultra-narrow width [J. C. Cuevas and F. S. Bergeret, Phys. Rev. Lett. 99, 217002 (2007)].
G.K. Strukova, G.V. Strukov, I.E. Batov, M.K. Sakharov, E.A. Kudrenko, and A.A. Mazilkin
Elsevier BV
I. E. Batov, Th. Schaepers, N. M. Chtchelkatchev, A. A. Golubov, H. Hardtdegen, and A. V. Ustinov
Allerton Press
A. A. Bannykh, J. Pfeiffer, V. S. Stolyarov, I. E. Batov, V. V. Ryazanov, and M. Weides
American Physical Society (APS)
The dependence of the critical current density ${j}_{c}$ on the ferromagnetic interlayer thickness ${d}_{F}$ was determined for $\\text{Nb}/{\\text{Al}}_{2}{\\text{O}}_{3}/\\text{Cu}/\\text{Ni}/\\text{Nb}$ Josephson tunnel junctions with ferromagnetic Ni interlayer thicknesses from very thin films $(\\ensuremath{\\sim}1\\text{ }\\text{nm})$ upward and classified into $F$-layer thickness regimes showing a dead magnetic layer, exchange, $\\text{exchange}+\\text{anisotropy}$ and total suppression of ${j}_{c}$. The Josephson coupling changes from 0 to $\\ensuremath{\\pi}$ as function of ${d}_{F}$, and\\char22{}very close to the crossover thickness\\char22{}as function of temperature. The strong suppression of the supercurrent in comparison to nonmagnetic $\\text{Nb}/{\\text{Al}}_{2}{\\text{O}}_{3}/\\text{Cu}/\\text{Nb}$ junctions indicated that the insertion of a $F$ layer leads to additional interface scattering. The transport inside the dead magnetic layer was in dirty limit. For the magnetically active regime fitting with both the clean and the dirty limit theories was carried out, indicating dirty limit condition, too. The results were discussed in the framework of literature.
Igor E. Batov, Thomas Schäpers, Nikolai M. Chtchelkatchev, Hilde Hardtdegen, and Alexey V. Ustinov
American Physical Society (APS)
We study the magnetotransport in small hybrid junctions formed by high-mobility ${\\mathrm{Ga}}_{x}{\\mathrm{In}}_{1\\ensuremath{-}x}\\mathrm{As}∕\\mathrm{In}\\mathrm{P}$ heterostructures coupled to superconducting (S) and normal metal (N) terminals. Highly transmissive superconducting contacts to a two-dimensional electron gas (2DEG) located in a ${\\mathrm{Ga}}_{x}{\\mathrm{In}}_{1\\ensuremath{-}x}\\mathrm{As}∕\\mathrm{In}\\mathrm{P}$ heterostructure are realized by using a $\\mathrm{Au}∕\\mathrm{Nb}\\mathrm{N}$ layer system. The magnetoresistance of the S/2DEG/N structures is studied as a function of dc bias current and temperature. At bias currents below a critical value, the resistance of the S/2DEG/N structures develops a strong oscillatory dependence on the magnetic field, with an amplitude of the oscillations considerably larger than that of the reference N/2DEG/N structures. The experimental results are qualitatively explained by taking into account Andreev reflection in high magnetic fields.
V. A. Gasparov, G. E. Tsydynzhapov, I. E. Batov, and Qi Li
AIP
I. E. Batov, X. Y. Jin, S. V. Shitov, Y. Koval, P. Müller, and A. V. Ustinov
AIP Publishing
We report the detection of electromagnetic radiation at about 500GHz from current-biased intrinsic Bi2Sr2CaCu2O8 single crystal Josephson junctions. We used two silicon lenses to quasioptically couple radiation from our samples to an integrated superconducting heterodyne receiver. The estimated maximum Josephson radiation power which reached the receiver antenna was about 1pW. We attribute the observed radiation to individual Josephson junctions of the stack and discuss a possibility of the phase locking of a larger number of junctions.
V. A. Gasparov, G. E. Tsydynzhapov, I. E. Batov, and Qi Li
Springer Science and Business Media LLC
V.A. Gasparov, G.E. Tsydynzhapov, I.E. Batov, and Qi Li
Springer Science and Business Media LLC
I. E. Batov, Th. Schäpers, A. A. Golubov, and A. V. Ustinov
AIP Publishing
We report on the fabrication of highly transparent superconductor∕normal metal∕two-dimensional electron gas junctions formed by a superconducting NbN electrode, a thin (10nm) Au interlayer, and a two-dimensional electron gas in an InGaAs∕InP heterostructure. High junction transparency has been achieved by exploiting developed process of Au∕NbN evaporation and rapid annealing at 400°C. This allowed us to observe a decrease in the differential resistance with pronounced double-dip structure within the superconducting energy gap in superconductor/two-dimensional electron gas (2DEG) proximity systems. The effect of a magnetic field perpendicular to the plane of the 2DEG on the differential resistance of the interface was studied. It has been found that the reduced subgap resistance remains in high magnetic fields. Zero-field data are analyzed within the previously established quasiclassical model for the proximity effect.
Publications
Scopus Author ID : 56078621300
GRANT DETAILS
- Russian Foundation for Basic Research (RFBR) project N 20-02-00864 “Study of coherent transport and nonlocal nonequilibrium effects in hybrid systems based on superconductors, ferromagnets, and semiconductor nanostructures”, 2020-2022
Principal Investigator
- Russian Foundation for Basic Research (RFBR) project N 17-02-00933 “Magnetotransport and electronic coherence effects in hybrid systems based on superconductors, ferromagnets and semiconductor nanostructures”, 2017-2019,
Principal Investigator
- Russian Foundation for Basic Research (RFBR) project N 14-02-01041 “Сoherent electronic transport in hybrid systems based on superconductors, ferromagnets and semiconductor nanostructures”, 2014-2017,
Principal Investigator
- Russian Foundation for Basic Research project N 17-02-01270 “Distributed Josephson structures including pi-junctions with ferromagnetic barrier”, 2017-2019,
- Ministry of Education and Science of the Russian Federation, Project N 14Y.26.31.0007 “Topological quantum phenomena in superconducting hybrid structures”, 2014-2018,
- Russian Science Foundation, Project N 14-12-01290, “Coherent transport investigation in nanostructures for superconducting electronics and spintronics devices”, 2014-2016
RESEARCH OUTPUTS (PATENTS, SOFTWARE, PUBLICATIONS, PRODUCTS)
1. C. Weyrich, T. Merzenich, J. Kampmeier, I.E. Batov, G. Mussler, J. Schubert, D. Gruetzmacher, Th. Schaepers, "Magnetoresistance oscillations in MBE-grown Sb2Te3 thin films",
Appl. Phys. Lett., v. 110, Iss. 9, p. 092104, 2017
DOI: 10.1063/1.4977848
2. A.V. Bubis, A.O. Denisov, S.U. Piatrusha, I.E. Batov, V.S. Khrapai, J. Becker, J. Treu, D. Ruhstorfer, G. Koblmüller, “Proximity effect and interface transparency in Al/InAs-nanowire/Al diffusive junctions”
Semicond. Sci. Technol., v.32, N 9, p. 094007, 2017
DOI: 10.1088/1361-6641/aa7eef
3. L.V. Ginzburg, I.E. Batov, V.V. Bol’ginov, S.V. Egorov, V.I. Chichkov, A.E. Shchegolev, N.V. Klenov, I.I. Soloviev, S.V. Bakurskiy, M.Yu. Kupriyanov, “Determination of the Current-Phase Relation in Josephson Junctions by Means of an Asymmetric Two-Junction SQUID”
JETP Letters, v. 107, Iss. 1, pp. 48-54, 2018
DOI: 10.1134/S0021364018010058
4. T.E. Golikova, M.J. Wolf, D. Beckmann, G.A. Penzyakov, I.E. Batov, I.V. Bobkova, A.M. Bobkov, V.V. Ryazanov,
“Controllable supercurrent in mesoscopic superconductor-normal metal-ferromagnet crosslike Josephson structures”
Supercond. Sci. Technol., vol. 34, N 9, p. 095001, 2021
DOI: 10.1088/1361-6668/abfd0d