Article
Multidisciplinary Sciences
Zheyi Zhu, Stephan Kim, Shiming Lei, Leslie M. Schoop, R. J. Cava, N. P. Ong
Summary: This study investigates the MAR features in high-transparency SNS junctions based on the Dirac semimetal MoTe2. It is found that MARs coexist with a Josephson supercurrent, and the amplitude of the supercurrent varies with the MAR order as the junction voltage is varied. The experiment measures the coherence of Cooper pairs shuttling across the junction and reveals a direct relation between the coherence and MARs. Surprisingly, the superconductivity in MoTe2 does not affect the MAR features.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Multidisciplinary
Shili Yan, Haitian Su, Dong Pan, Weijie Li, Zhaozheng Lyu, Mo Chen, Xingjun Wu, Li Lu, Jianhua Zhao, Ji-Yin Wang, Hongqi Xu
Summary: We conducted an experimental study on proximity-induced superconductivity in planar Josephson junction devices using free-standing InAs nanosheets. The nanosheets were grown by molecular beam epitaxy, and the devices were fabricated by directly contacting the nanosheets with Al electrodes. Low-temperature measurements showed gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions were analyzed based on the BCS theory at different magnetic fields and temperatures. The ac Josephson effect measurements under microwave radiation revealed the observation of integer Shapiro steps. This work demonstrates the potential of InAs nanosheet-based hybrid devices for exploring the forefront of physics, such as two-dimensional topological superconductivity.
Article
Chemistry, Physical
Maxim M. Korshunov, Svetoslav A. Kuzmichev, Tatiana E. Kuzmicheva
Summary: We directly observed temperature-dependent spin excitons in the Andreev spectra of iron-based superconductors. Our observation, combined with other experimental evidence, confirms the extended s-wave order parameter symmetry and indirectly supports the spin-fluctuation mechanism of Cooper pairing.
Article
Materials Science, Multidisciplinary
Lu Gao, Qiang Cheng, Qing-Feng Sun
Summary: In this study, we investigate the Andreev reflections and quantum transport in the proximitized graphene/superconductor junction. We find that the presence of pseudospin staggered potential and intrinsic spin-orbit coupling in the junction leads to spin-valley dependent double Andreev reflections and anomalous transport properties. These spin-valley dependent Andreev reflections offer a way to detect the induced potential and coupling in graphene and establish the foundation of superconductor electronics based on spin-valley indices.
Article
Materials Science, Multidisciplinary
Rak-Hee Kim, Nam-Hee Kim, Bongkeon Kim, Yasen Hou, Dong Yu, Yong-Joo Doh
Summary: Superconducting proximity junctions made of topological insulator nanoribbons offer a useful platform for studying topological superconductivity. In this study, Josephson junctions using Sb-doped Bi2Se3 nanoribbons in contact with Al electrodes were fabricated and measured. The observations of Aharonov-Bohm and Altshuler-Aronov-Spivak oscillations in the axial magneto-conductance of the nanoribbons indicate the presence of metallic surface states.
CURRENT APPLIED PHYSICS
(2022)
Article
Physics, Applied
Sedighe Salimian, Matteo Carrega, Isha Verma, Valentina Zannier, Michal P. Nowak, Fabio Beltram, Lucia Sorba, Stefan Heun
Summary: High-quality InSb nanoflags, as a versatile III-V semiconductor material, show great potential in advanced quantum technologies, especially in realizing topological superconducting states. Fabrication of ballistic Josephson-junction devices based on InSb nanoflags allows for tunable proximity-induced supercurrent, indicating a promising platform for future quantum applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Multidisciplinary Sciences
Svetoslav Kuzmichev, Tatiana Kuzmicheva, Igor Morozov, Alexander Boltalin, Andrey Shilov
Summary: The structure of the superconducting order parameter in LiFeAs is studied using incoherent multiple Andreev reflections effect (IMARE) spectroscopy. SnS junctions show the presence of at least three bulk superconducting order parameters in LiFeAs, and we discuss their symmetry.
SN APPLIED SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Da Wang, Evan J. Telford, Avishai Benyamini, John Jesudasan, Pratap Raychaudhuri, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory R. Dean, Abhay N. Pasupathy
Summary: Hybrid superconductor/graphene junctions were investigated for correlations between Cooper pairs and quantum Hall edge modes, showing that the graphene's Dirac band structure affects Andreev reflections and their spectrum can be dynamically tuned with parallel magnetic fields. Additionally, perpendicular magnetic fields led to an oscillatory suppression of 2-probe conductance in the nu = 4 Landau level, consistent with reduced efficiency of Andreev processes at the NbN/g interface as predicted theoretically.
Article
Chemistry, Multidisciplinary
Damon James Carrad, Lukas Stampfer, Dags Olsteins, Christian Emmanuel Noes Petersen, Sabbir A. Khan, Peter Krogstrup, Thomas Sand Jespersen
Summary: Semiconductor/superconductor hybrids have been studied to explore novel physics and develop new technologies. In this study, Josephson junctions defined by shadow epitaxy on InAsSb/Al nanowires were investigated. The devices exhibited gate-tunable supercurrents at low temperatures and multiple Andreev reflections at finite voltage bias. Under microwave irradiation, characteristic oscillating sidebands at quantized energies were observed, which confirmed a recently suggested modification of a classical equation. The measurements provided evidence for the effective charge transferred by the tunneling process and suggested photon-assisted tunneling as a powerful method for identifying low-energy spectral features in hybrid Josephson devices.
Article
Physics, Applied
Xue Yang, Pablo Burset, Bo Lu
Summary: In a four-terminal setup, researchers found that a quantum spin Hall strip with different edges contacted by s-wave superconductors can exhibit Majorana bound states protected by time-reversal symmetry. They observed a subharmonic gap structure in the conductance peaks from multiple Andreev reflections, which is sensitive to the phase difference between the superconductors. This phase difference also controls an even-odd effect, where odd spikes disappear and even spikes split when the Majorana states form or when the superconductors have different gap sizes.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Giulia Venditti, Marco Grilli, Sergio Caprara
Summary: LaAlO3/SrTiO3 interfaces are two-dimensional electron gases that can have their carrier density controlled to alter their electrical properties. These interfaces have complex band structures and exhibit superconductivity. Understanding the finite-bandwidth effects of these interfaces is important, especially in studying the critical temperature of heavily disordered multi-gap superconductors.
Article
Physics, Applied
Tobias W. Schmitt, Benedikt Frohn, Wilhelm Wittl, Abdur R. Jalil, Michael Schleenvoigt, Erik Zimmermann, Anne Schmidt, Thomas Schaepers, Juan Carlos Cuevas, Alexander Brinkman, Detlev Gruetzmacher, Peter Schueffelgen
Summary: In this study, the temperature-dependent behavior of a Bi2Te3-based Josephson junction (JJ) with transparent interfaces is investigated, providing insights into the contributions of bulk and surface states in topological insulator JJs. Differential conductance spectra of multiple Andreev reflections (MARs) are measured in electrical transport experiments, showing a qualitative temperature-dependent change from peak features to dip features. The observation of both types of MAR patterns in a single JJ suggests the presence of diffusive bulk and ballistic surface states, and their connection to the temperature dependence of the critical current. This work advances the understanding of induced superconductivity in topological insulators and offers new avenues for studying induced superconductivity in the topological surface states of these materials.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Xianxin Wu, Xin Liu, Ronny Thomale, Chao-Xing Liu
Summary: In this research, we propose to create Majorana zero modes (MZMs) without heterostructures in the FeTe1-xSex monolayer by applying an in-plane magnetic field and tuning the local chemical potential via electric gating. Our study not only reveals the FeTe1-xSex monolayer as a promising Majorana platform with scalability and electrical tunability, but also provides a general principle to search for realistic realization of high-order topological superconductivity.
NATIONAL SCIENCE REVIEW
(2022)
Article
Physics, Multidisciplinary
Artem V. Polkin, Pavel A. Ioselevich
Summary: In this study, we investigate Multiple Andreev Reflections in long diffusive superconductor-normal metal-superconductor junctions with low-transparency interfaces. We find that at intermediate temperatures, the induced current is dominated by noncoherent multiple Andreev reflections, and this effect relies on thermalization. Furthermore, we discover that a ferromagnetic junction produces a non-trivial splitting of the subharmonic gap structure.
Review
Physics, Multidisciplinary
Jinghui Wang, Yueshen Wu, Xiang Zhou, Yifei Li, Bolun Teng, Peng Dong, Jiadian He, Yiwen Zhang, Yifan Ding, Jun Li
Summary: Despite over ten years of research, the superconducting mechanism of iron-based superconductors remains unresolved. High-temperature superconductivity is associated with magnetic suppression and electronic state changes, but direct evidence linking these transitions to superconductivity is still lacking.
ADVANCES IN PHYSICS-X
(2021)
Article
Chemistry, Physical
Maria Markina, Tatyana Vasilchikova, Elena Kuznetsova, Peter Berdonosov, Andrey Olenev, Seung Hwan Chung, Hyun-Joo Koo, Myung-Hwan Whangbo, Alexander Vasiliev
Summary: We synthesized and characterized the solid solutions Cu3Bi(Se(1-x)TexO(3))(2)O2Br (x = 0, 0.25, 0.5, 0.75, 1) for the first time. The interlayer antiferromagnetic (AFM) coupling in francisites was found to be due to interlayer high-spin orbital interaction across the van der Waals (vdW) gaps rather than interlayer spin exchange. We proposed a method to modify francisites to create oxide vdW ferromagnets.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Maxim A. Blagov, Nataliya G. Spitsyna, Nikolai S. Ovanesyan, Anatolii S. Lobach, Leokadiya V. Zorina, Sergey V. Simonov, Konstantin V. Zakharov, Alexander N. Vasiliev
Summary: A new iron(III) anionic complex based on a pyruvic acid thiosemicarbazone ligand has been synthesized and characterized. The compound exhibits a spin-crossover transition from the low-spin to the high-spin state above 250 K. It was also found that the lithium cation has an influence on the stabilization of the low-spin state.
DALTON TRANSACTIONS
(2023)
Article
Physics, Applied
Y. A. Ovchenkov, D. A. Chareev, D. E. Presnov, O. S. Volkova, A. N. Vasiliev
Summary: In this study, the transport properties of FeSe1-xTex and pure FeSe crystals were compared. The results showed significant differences in structural transitions and temperature dependence between the two, suggesting a change in the ground state and the presence of quantum criticality. Furthermore, the phase diagram of FeSe1-xTex at low x resembled that of FeSe under pressure.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2023)
Article
Chemistry, Physical
Alisher F. Murtazoev, Konstantin A. Lyssenko, Maria M. Markina, Valery A. Dolgikh, Alexander N. Vasiliev, Peter S. Berdonosov
Summary: A new family of compounds with the formula ACu(7)TeO(4)(SO4)(5)Cl (A=Na, K, Rb, Cs) isostructural to mineral Nabokoite (K species) was synthesized and characterized. These compounds exhibit interesting properties as quasi-two-dimensional magnets with a square kagome lattice geometry. The presence of wavy and distorted triangles in the lattice, along with additional magnetic ions, adds complexity to the magnetism of these compounds. The interaction of the magnetic ions through virtual excitations of the lattice leads to the coexistence of long-range magnetic order and spin liquid behavior.
Article
Physics, Multidisciplinary
M. V. Golubkov, V. A. Stepanov, A. V. Sadakov, A. S. Usol'tsev, I. V. Morozov
Summary: The characteristics of point Josephson contacts Pb0.6In0.4/KFe2As2 and KFe2As2/KFe2As2 were studied. The temperature dependence of characteristic contact voltages V-C(T) and the dependence of the first current step amplitudes in I-V characteristics on the power of 7.6-GHz electromagnetic radiation were measured. It was found that V-C(T) curves for all contacts can be described in terms of the SIS*IS contact model for superconductors with the s-symmetry of order parameter. It was also proven that the current step oscillation period as a function of microwave power can be approximated with the resistive model of contact with I-S = I(C)sin(phi). The obtained data are consistent with the normal s-symmetry of order parameter.
JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
T. E. Kuzmicheva, S. A. Kuzmichev, K. S. Pervakov, V. A. Vlasenko
Summary: We compare the structure of superconducting order parameter of overdoped BaFe1.88Ni0.12As2 and underdoped BaFe1.92Ni0.08As2 pnictides with similar T-c around 18.0-18.3 K. Using spectroscopy, we directly determine the magnitudes of the two microscopic superconducting order parameters and discuss their similarity, difference, and possible influence of antiferromagnetic phase on superconducting properties.
Article
Chemistry, Physical
Andrey V. Sadakov, Vladimir A. Vlasenko, Ivan A. Troyan, Oleg A. Sobolevskiy, Dmitrii V. Semenok, Di Zhou, Vladimir M. Pudalov
Summary: A comprehensive study was conducted on vortex phases and dynamics in the high-temperature superconductor YH(6) under a pressure of 200 GPa. The thermal activation energy and its dependence on magnetic field were analyzed using the thermally activated flux flow (TAFF) theory. The vortex phase transition from vortex glass to vortex liquid was studied, and a vortex phase diagram was constructed for superhydrides for the first time. The high flux flow barriers and crossover fields make YH6 an outstanding superconductor compared to other materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Leonid Morgun, Svetoslav Kuzmichev, Igor Morozov, Alena Degtyarenko, Andrey Sadakov, Andrey Shilov, Ilya Zhuvagin, Yevgeny Rakhmanov, Tatiana Kuzmicheva
Summary: A comprehensive study of the superconducting properties of underdoped NaFe0.979Co0.021As single crystals is presented, using a combination of upper critical field measurements and incoherent multiple Andreev reflection effect (IMARE) spectroscopy. The study reveals the temperature dependence of the Hc2(T) and the characteristics of the superconducting order parameters.
Article
Chemistry, Multidisciplinary
Ivan A. Troyan, Dmitrii V. Semenok, Anna G. Ivanova, Andrey V. Sadakov, Di Zhou, Alexander G. Kvashnin, Ivan A. Kruglov, Oleg A. Sobolevskiy, Marianna V. Lyubutina, Dmitry S. Perekalin, Toni Helm, Stanley W. Tozer, Maxim Bykov, Alexander F. Goncharov, Vladimir M. Pudalov, Igor S. Lyubutin
Summary: The chemical interaction of Sn with H-2 was studied using X-ray diffraction methods, revealing the superconducting properties and structure of SnH4 tetrahydride, as well as several lower hydrides. SnH4 showed unusual behavior in strong magnetic fields and its electrical resistance temperature dependence did not follow conventional theories. These findings suggest that superhydrides are more similar to cuprates than previously believed.
Article
Chemistry, Multidisciplinary
Marwa H. A. Aouelela, Mohamed Taha, Samaa I. El-dek, Abdelwahab Hassan, Alexander N. Vasiliev, Mahmoud Abdel-Hafiez
Summary: During the past decade, two-dimensional layered materials have attracted much attention due to their unique physical and electronic properties, providing new opportunities for the exploration of novel physics and devices. Among these materials, iron selenide has become a focus of interest for physicists as a potential platform for developing new superconductors. Chemical doping is a powerful approach to manipulate and optimize the electronic structure and physical properties of materials. This study investigates the effects of molybdenum and sulfur doping on the physical properties of FeSe through complementary measurements and theoretical calculations, offering insights into the influence of doping on the superconducting properties of FeSe.
Article
Chemistry, Inorganic & Nuclear
A. F. Murtazoev, P. S. Berdonosov, K. A. Lyssenko, V. A. Dolgikh, M. Y. Geidorf, O. S. Volkova, H. -J Koo, M. -H Whangbo, A. N. Vasiliev
Summary: We synthesized a new compound, Co-3(SeO3)(SeO4)(OH)(2), with a kagome-like arrangement of Co2+ ions. The compound exhibits three successive magnetic transitions at low temperatures and a 1/3-magnetization plateau. The magnetic phase diagram shows three magnetic phases, with phase I being antiferromagnetic and phases II and III being responsible for the 1/3-magnetization plateau. To understand these magnetic properties, spin-polarized DFT+U calculations were performed to evaluate the spin exchanges in the compound.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Alisher F. Murtazoev, Peter S. Berdonosov, Konstantin A. Lyssenko, Valery A. Dolgikh, Zlata V. Pchelkina, Konstantin V. Zakharov, Michael Y. Geidorf, Tatyana M. Vasilchikova, Olga S. Volkova, Alexander N. Vasiliev
Summary: Anhydrous copper tellurite sulfate, Cu3TeO3(SO4)(2), was synthesized via vapor transport reactions in sealed silica glass ampoules. Various measurements revealed long-range antiferromagnetic order at T-N = 13 K and established an H-T magnetic phase diagram. Density functional theory calculations provided estimations of leading exchange interaction parameters.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Roman V. Bazhan, Vladimir B. Nalbandyan, Tatyana M. Vasilchikova, Hyun-Joo Koo, Myung-Hwan Whangbo, Alexander N. Vasiliev
Summary: The missing member of the rosiaite family, CoGeTeO6, was synthesized and characterized. It exhibits short- and long-range magnetic ordering at different temperatures and its magnetic structure consists of three-dimensional antiferromagnetic lattices. The experimental and computational results show good agreement under different ion treatments.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Aleksandr Sh. Samarin, Ivan A. Trussov, Zlata V. Pchelkina, Stanislav S. Fedotov, Yevgeniy A. Ovchenkov, Sergei V. Zhurenko, Alexei V. Tkachev, Andrei A. Gippius, Larisa V. Shvanskaya, Alexander N. Vasiliev
Summary: A novel vanadium hydroxide-phosphate, NH4VPO4OH, has been synthesized hydrothermally at 230 degrees C. The compound shows a rare case of Haldane spin system with spin S=1 based on V3+ ions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
A. A. Vorobyova, K. A. Lyssenko, G. D. Chistyakov, I. V. Morozov, Y. A. Ovchenkov, T. M. Vasilchikova, H. -J. Koo, M. -H. Whangbo, O. S. Volkova, A. N. Vasiliev
Summary: This study reports the structure, magnetic and thermal properties of PyH)CsCo2(NO3)(6) crystals obtained from a nitric acid solution. The results reveal that the crystal exhibits long-range canted antiferromagnetic ordering and possesses easy-axis magnetic anisotropy.
DALTON TRANSACTIONS
(2023)
