Size-selected linear sp-carbon chain molecules of hydrogen-capped polyyne C12H2 are dispersed in stretched polyvinyl alcohol (PVA) films to align them along the direction of stretching of the film. The order parameter for anisotropic molecular orientation is determined from the angular dependence of UV absorption band intensities using linearly polarized incident light. Phosphorescence spectra at cryogenic temperature of 20 K of aligned C12H2 polyyne molecules in the stretched PVA film exhibit anisotropic properties, namely linearly polarized luminescence (LPL). Molecular orientation is modeled by the |cosθ|N distribution of linear molecules to simulate angle-dependent polarized optical emission intensities. The ensemble of aligned polyyne molecules is demonstrated to be an ideal molecular system for consideration of linear dichroism in LPL as well as in photo absorption.
{"title":"Linearly polarized luminescence of polyyne molecules aligned in PVA films","authors":"Tomonari Wakabayashi, Yuri Fujii, Yuya Ikeda, Keito Morimoto, Nanase Kohno, Hal Suzuki","doi":"10.1063/10.0028168","DOIUrl":"https://doi.org/10.1063/10.0028168","url":null,"abstract":"Size-selected linear sp-carbon chain molecules of hydrogen-capped polyyne C12H2 are dispersed in stretched polyvinyl alcohol (PVA) films to align them along the direction of stretching of the film. The order parameter for anisotropic molecular orientation is determined from the angular dependence of UV absorption band intensities using linearly polarized incident light. Phosphorescence spectra at cryogenic temperature of 20 K of aligned C12H2 polyyne molecules in the stretched PVA film exhibit anisotropic properties, namely linearly polarized luminescence (LPL). Molecular orientation is modeled by the |cosθ|N distribution of linear molecules to simulate angle-dependent polarized optical emission intensities. The ensemble of aligned polyyne molecules is demonstrated to be an ideal molecular system for consideration of linear dichroism in LPL as well as in photo absorption.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"87 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matrix isolation infrared absorption spectroscopy was combined with quantum chemical calculations to characterize valeric acid conformers. Geometries and vibrational spectra of possible valeric acid conformers were calculated using MP2 and B3LYP levels of theory. MP2 calculations predict that the most stable form of valeric acid is a nonlinear aliphatic chain conformer, this contradicts B3LYP findings. Infrared absorption spectra of valeric acid isolated in argon and neon matrices exhibit complicated band structures suggesting the presence of more than one structure of valeric acid trapped in the matrices. A comparison of calculated and experimental spectra allowed us to conclude that three conformers are trapped in argon and neon matrices. Two of them, the linear chain called here TTTT and nonlinear TGTT, are found in equal distribution while the third one GGTT is less populated, at the 1:3 ratio to the most stable one.
{"title":"Conformers of valeric acid: Matrix isolation infrared spectroscopy study","authors":"J. Mačytė, V. Šablinskas, J. Čeponkus","doi":"10.1063/10.0028181","DOIUrl":"https://doi.org/10.1063/10.0028181","url":null,"abstract":"Matrix isolation infrared absorption spectroscopy was combined with quantum chemical calculations to characterize valeric acid conformers. Geometries and vibrational spectra of possible valeric acid conformers were calculated using MP2 and B3LYP levels of theory. MP2 calculations predict that the most stable form of valeric acid is a nonlinear aliphatic chain conformer, this contradicts B3LYP findings. Infrared absorption spectra of valeric acid isolated in argon and neon matrices exhibit complicated band structures suggesting the presence of more than one structure of valeric acid trapped in the matrices. A comparison of calculated and experimental spectra allowed us to conclude that three conformers are trapped in argon and neon matrices. Two of them, the linear chain called here TTTT and nonlinear TGTT, are found in equal distribution while the third one GGTT is less populated, at the 1:3 ratio to the most stable one.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"127 16 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. L. Bashlakov, O. E. Kvitnitskaya, S. Aswartham, G. Shipunov, L. Harnagea, D. V. Efremov, B. Büchner, Yu. G. Naidyuk
VS2 and VSe2 have attracted particular attention among the transition metals dichalcogenides because of their promising physical properties concerning magnetic ordering, charge density wave (CDW), emergent superconductivity, etc., which are very sensitive to stoichiometry and dimensionality reduction. Yanson point-contact (PC) spectroscopic study reveals metallic and nonmetallic states in VS2 PCs, as well as a magnetic phase transition, was detected near 20 K. The rare PC spectra, where the magnetic phase transition was not visible, show a broad maximum of around 20 mV, likely connected with electron-phonon interaction (EPI). The PC spectra of VSe2 demonstrate metallic behavior, which allowed us to detect features associated with EPI and CDW transition. The Kondo effect appeared for both compounds, apparently due to interlayer vanadium ions. Besides, the resistive switching was observed in PCs on VSe2 between a low resistive, mainly metallic-type state, and a high resistive nonmetallic-type state by applying bias voltage (about 0.4 V). Reverse switching occurs by applying a voltage of opposite polarity (about 0.4 V). The reason may be the alteration of stoichiometry in the PC core due to the displacement of V ions to interlayer under a high electric field. The observed resistive switching characterizes VSe2 as a potential material, e.g., for non-volatile resistive RAM, neuromorphic engineering, and other nanoelectronic applications. Per contra, VS2 attracts attention as a rare layered van der Waals compound with magnetic transition.
{"title":"Electron-phonon interaction, magnetic phase transition, charge density waves, and resistive switching in VS2 and VSe2 revealed by Yanson point-contact spectroscopy","authors":"D. L. Bashlakov, O. E. Kvitnitskaya, S. Aswartham, G. Shipunov, L. Harnagea, D. V. Efremov, B. Büchner, Yu. G. Naidyuk","doi":"10.1063/10.0027924","DOIUrl":"https://doi.org/10.1063/10.0027924","url":null,"abstract":"VS2 and VSe2 have attracted particular attention among the transition metals dichalcogenides because of their promising physical properties concerning magnetic ordering, charge density wave (CDW), emergent superconductivity, etc., which are very sensitive to stoichiometry and dimensionality reduction. Yanson point-contact (PC) spectroscopic study reveals metallic and nonmetallic states in VS2 PCs, as well as a magnetic phase transition, was detected near 20 K. The rare PC spectra, where the magnetic phase transition was not visible, show a broad maximum of around 20 mV, likely connected with electron-phonon interaction (EPI). The PC spectra of VSe2 demonstrate metallic behavior, which allowed us to detect features associated with EPI and CDW transition. The Kondo effect appeared for both compounds, apparently due to interlayer vanadium ions. Besides, the resistive switching was observed in PCs on VSe2 between a low resistive, mainly metallic-type state, and a high resistive nonmetallic-type state by applying bias voltage (about 0.4 V). Reverse switching occurs by applying a voltage of opposite polarity (about 0.4 V). The reason may be the alteration of stoichiometry in the PC core due to the displacement of V ions to interlayer under a high electric field. The observed resistive switching characterizes VSe2 as a potential material, e.g., for non-volatile resistive RAM, neuromorphic engineering, and other nanoelectronic applications. Per contra, VS2 attracts attention as a rare layered van der Waals compound with magnetic transition.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"42 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Filip Košuth, Johan Cedervall, Gustav Ek, Slavomír Gabáni, Gabriel Pristáš, Matúš Orendáč, Július Bačkai, Oleksandr Onufriienko, Pavol Szabó, Karol Flachbart
We have prepared and investigated superconducting equimolar medium-entropy alloys of TiZrNb and TiZrNbHf. Their basic superconducting parameters, as the values of the critical temperature Tc, upper critical magnetic field Bc2 and the superconducting energy gap Δ have been studied with the use of magnetic susceptibility and point-contact Andreev reflection (PCAR) spectroscopy measurements. Although our samples have different critical temperatures, namely Tc ∼ 8.2 K for TiZrNb and Tc ∼ 6.3 K for TiZrNbHf, their zero-temperature critical magnetic field has the same value Bc2(0) = 12 T, from the vicinity of the Clogston limit. We have observed the presence of degraded phases on the surfaces of all the investigated samples using PCAR measurements. Still, we were able to show that the bulk phase in both systems exhibits BCS weakly coupled superconductivity with 2Δ(0)/kBTc ∼ 3.5.
{"title":"Superconductivity in TiZrNb and TiZrNbHf bulk equimolar alloys","authors":"Filip Košuth, Johan Cedervall, Gustav Ek, Slavomír Gabáni, Gabriel Pristáš, Matúš Orendáč, Július Bačkai, Oleksandr Onufriienko, Pavol Szabó, Karol Flachbart","doi":"10.1063/10.0027922","DOIUrl":"https://doi.org/10.1063/10.0027922","url":null,"abstract":"We have prepared and investigated superconducting equimolar medium-entropy alloys of TiZrNb and TiZrNbHf. Their basic superconducting parameters, as the values of the critical temperature Tc, upper critical magnetic field Bc2 and the superconducting energy gap Δ have been studied with the use of magnetic susceptibility and point-contact Andreev reflection (PCAR) spectroscopy measurements. Although our samples have different critical temperatures, namely Tc ∼ 8.2 K for TiZrNb and Tc ∼ 6.3 K for TiZrNbHf, their zero-temperature critical magnetic field has the same value Bc2(0) = 12 T, from the vicinity of the Clogston limit. We have observed the presence of degraded phases on the surfaces of all the investigated samples using PCAR measurements. Still, we were able to show that the bulk phase in both systems exhibits BCS weakly coupled superconductivity with 2Δ(0)/kBTc ∼ 3.5.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"113 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Jonson, R. I. Shekhter, O. Entin-Wohlman, A. Aharony
On the occasion of the 50th anniversary of point-contact spectroscopy, we review and extend some of our recent studies on the effects of spin-orbit interactions located at an electric point contact connecting two bulk superconductors. In particular, we study the effects on the Josephson tunneling of Cooper pairs between the superconductors. We demonstrate that such tunneling forces the electronic spin to fluctuate quantum mechanically, transforming a BCS condensate into a quantum superposition of singlet and triplet pairs. The relative prevalence of those pairs can be controlled electrostatically and mechanically. The singlet pairs contribute to the Josephson charge current flowing through the point contact but not to the Josephson spin current injected into the superconductors. The spin-polarized pairs contribute to the injected Josephson spin current but not to the superconducting charge flow. These results allow for new functionalities of spin-active Josephson junctions.
{"title":"Josephson tunneling controlled by spin-orbit interaction","authors":"M. Jonson, R. I. Shekhter, O. Entin-Wohlman, A. Aharony","doi":"10.1063/10.0027927","DOIUrl":"https://doi.org/10.1063/10.0027927","url":null,"abstract":"On the occasion of the 50th anniversary of point-contact spectroscopy, we review and extend some of our recent studies on the effects of spin-orbit interactions located at an electric point contact connecting two bulk superconductors. In particular, we study the effects on the Josephson tunneling of Cooper pairs between the superconductors. We demonstrate that such tunneling forces the electronic spin to fluctuate quantum mechanically, transforming a BCS condensate into a quantum superposition of singlet and triplet pairs. The relative prevalence of those pairs can be controlled electrostatically and mechanically. The singlet pairs contribute to the Josephson charge current flowing through the point contact but not to the Josephson spin current injected into the superconductors. The spin-polarized pairs contribute to the injected Josephson spin current but not to the superconducting charge flow. These results allow for new functionalities of spin-active Josephson junctions.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"3 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Satariano, A. F. Volkov, H. G. Ahmad, L. Di Palma, R. Ferraiuolo, Z. Iqbal, A. Vettoliere, C. Granata, D. Montemurro, L. Parlato, G. P. Pepe, F. Tafuri, G. Ausanio, D. Massarotti
Magnetic Josephson junctions (MJJs) are a special class of hybrid systems where antagonistic correlations coexist, thus providing a key for advances in weak superconductivity, superconducting spintronics, and quantum computation. So far, the memory properties of MJJs have been mostly investigated in view of digital electronics and for spintronic devices at liquid-helium temperature. At the operating temperature of quantum circuits, a magnetic order can rise in a superconductor (S) at the S/ferromagnet (F) interface, i.e., the inverse proximity effect (IPE), thus leading to a significant modification of the magnetic field patterns in MJJs. In this work, we have carried out a comparative investigation of the magnetic behavior of tunnel MJJs with a strong ferromagnetic layer inserted in the layout of both Nb and Al JJs, respectively. The comparative analysis validates the crucial role of the temperature, the fundamental scaling energies of S/F coupling systems, and the transparency of the S/F interface. This investigation points out that the IPE is a key aspect to consider when designing tunnel MJJs operating well below 4 K and thus in the perspective of hybrid superconducting quantum architectures.
{"title":"Evidence of the inverse proximity effect in tunnel magnetic josephson junctions","authors":"R. Satariano, A. F. Volkov, H. G. Ahmad, L. Di Palma, R. Ferraiuolo, Z. Iqbal, A. Vettoliere, C. Granata, D. Montemurro, L. Parlato, G. P. Pepe, F. Tafuri, G. Ausanio, D. Massarotti","doi":"10.1063/10.0027923","DOIUrl":"https://doi.org/10.1063/10.0027923","url":null,"abstract":"Magnetic Josephson junctions (MJJs) are a special class of hybrid systems where antagonistic correlations coexist, thus providing a key for advances in weak superconductivity, superconducting spintronics, and quantum computation. So far, the memory properties of MJJs have been mostly investigated in view of digital electronics and for spintronic devices at liquid-helium temperature. At the operating temperature of quantum circuits, a magnetic order can rise in a superconductor (S) at the S/ferromagnet (F) interface, i.e., the inverse proximity effect (IPE), thus leading to a significant modification of the magnetic field patterns in MJJs. In this work, we have carried out a comparative investigation of the magnetic behavior of tunnel MJJs with a strong ferromagnetic layer inserted in the layout of both Nb and Al JJs, respectively. The comparative analysis validates the crucial role of the temperature, the fundamental scaling energies of S/F coupling systems, and the transparency of the S/F interface. This investigation points out that the IPE is a key aspect to consider when designing tunnel MJJs operating well below 4 K and thus in the perspective of hybrid superconducting quantum architectures.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"59 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an experimental study of the spin rectification effects produced by ferromagnetic resonance in a NiFe wire. A system of four independent nonmagnetic contact probes was used to supply both rf and dc currents to the wire and to measure dc voltages at different locations in the wire. The rf current drives the ferromagnet’s magnetization into resonance and produces a dc photovoltage which results from the rectification of rf current in the ferromagnet with oscillating magnetization. Our 4-probe system provided a means to detect the photovoltage and separate contributions from the ferromagnet/nonmagnet contacts and the bulk of the ferromagnet. The contact photovoltage was found to increase approximately linearly with the dc bias applied to the wire. In contrast, the bulk contribution was found to be almost independent of the dc bias. By tuning properties of individual contact probes we were able to change the magnitude of the contact photovoltage and even reverse its sign. Our results highlight the different contributions to photovoltage and the importance of contact properties/nonlinearities for rectification effects in spintronic devices.
{"title":"Contact and bulk rectification effects in ferromagnetic resonance experiments","authors":"Md. Majibul Haque Babu, Maxim Tsoi","doi":"10.1063/10.0027925","DOIUrl":"https://doi.org/10.1063/10.0027925","url":null,"abstract":"We present an experimental study of the spin rectification effects produced by ferromagnetic resonance in a NiFe wire. A system of four independent nonmagnetic contact probes was used to supply both rf and dc currents to the wire and to measure dc voltages at different locations in the wire. The rf current drives the ferromagnet’s magnetization into resonance and produces a dc photovoltage which results from the rectification of rf current in the ferromagnet with oscillating magnetization. Our 4-probe system provided a means to detect the photovoltage and separate contributions from the ferromagnet/nonmagnet contacts and the bulk of the ferromagnet. The contact photovoltage was found to increase approximately linearly with the dc bias applied to the wire. In contrast, the bulk contribution was found to be almost independent of the dc bias. By tuning properties of individual contact probes we were able to change the magnitude of the contact photovoltage and even reverse its sign. Our results highlight the different contributions to photovoltage and the importance of contact properties/nonlinearities for rectification effects in spintronic devices.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"77 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proximity-coupled nanostructures of conventional superconductors (SCs) and half-metallic ferromagnets (hmFs) are promising candidates as materials with unconventional superconductivity. The interrelated superposition of spin singlet-triplet and frequency even-odd superconducting condensates characterizes the superconducting state in such heterostructures. In a multi-band SC, the collective modes associated with the excitations of the relative phase between superconducting bands without perturbation of the Cooper pairs symmetry (Leggett modes) are allowed. In this report, we present the results of experimental investigations via the point-contact transport measurements of the Leggett-like collective excitations in the superconducting state of the nanocomposite of s-wave two-band superconductor MgB2 and half-metallic ferromagnet (La,Sr)MnO3. Two types of point contacts (PCs) have been used: the nanocomposite-nonmagnetic metal PCs and the nanocomposite–hmF PCs. The conductance equidistant peaks against the background of the gap structure were observed in both types of high-quality point junctions. Their distinctive feature was their period: two times shorter for the nanocomposite–hmF contacts compared to the nonmagnetic metal PCs. We attribute these spin-selective conductance periodic peaks to the relative phase Leggett’s excitations between “parents” MgB2 even-frequency singlet condensates and proximity-induced triplet superconducting condensates. The data obtained on the hmF PCs also demonstrate the features that may indicate a dynamic coupling between even-frequency condensates and odd-frequency gapless superconducting condensates.
传统超导体（SC）和半金属铁磁体（hmF）的近距离耦合纳米结构是具有非常规超导性的候选材料。自旋单三态和频率偶多态超导凝聚态的相互叠加是这类异质结构中超导态的特征。在多带超导中，允许出现与超导带间相对相位激发相关的集体模式，而不会扰动库珀对对称性（莱格特模式）。在本报告中，我们介绍了通过点接触输运测量对 s 波双带超导体 MgB2 和半金属铁磁体 (La,Sr)MnO3 的纳米复合材料超导态中的莱格特类集体激发进行实验研究的结果。使用了两种类型的点接触（PCs）：纳米复合材料-非磁性金属 PCs 和纳米复合材料-hmF PCs。在这两种类型的高质量点结中都观察到了以间隙结构为背景的等距电导峰。它们的显著特点是周期：与无磁金属 PC 相比，纳米复合材料-hmF 触点的周期短两倍。我们将这些自旋选择性电导周期性峰值归因于 "母体 "MgB2 偶频单次凝聚态和近距离诱导的三重超导凝聚态之间的相对莱格特相位激发。在 hmF PC 上获得的数据还显示了偶频凝聚态与奇频无间隙超导凝聚态之间可能存在动态耦合的特征。
{"title":"Point-contact spectroscopy of Leggett modes in superconducting compounds with unconventional pairing","authors":"V. N. Krivoruchko, V. Yu. Tarenkov","doi":"10.1063/10.0027921","DOIUrl":"https://doi.org/10.1063/10.0027921","url":null,"abstract":"Proximity-coupled nanostructures of conventional superconductors (SCs) and half-metallic ferromagnets (hmFs) are promising candidates as materials with unconventional superconductivity. The interrelated superposition of spin singlet-triplet and frequency even-odd superconducting condensates characterizes the superconducting state in such heterostructures. In a multi-band SC, the collective modes associated with the excitations of the relative phase between superconducting bands without perturbation of the Cooper pairs symmetry (Leggett modes) are allowed. In this report, we present the results of experimental investigations via the point-contact transport measurements of the Leggett-like collective excitations in the superconducting state of the nanocomposite of s-wave two-band superconductor MgB2 and half-metallic ferromagnet (La,Sr)MnO3. Two types of point contacts (PCs) have been used: the nanocomposite-nonmagnetic metal PCs and the nanocomposite–hmF PCs. The conductance equidistant peaks against the background of the gap structure were observed in both types of high-quality point junctions. Their distinctive feature was their period: two times shorter for the nanocomposite–hmF contacts compared to the nonmagnetic metal PCs. We attribute these spin-selective conductance periodic peaks to the relative phase Leggett’s excitations between “parents” MgB2 even-frequency singlet condensates and proximity-induced triplet superconducting condensates. The data obtained on the hmF PCs also demonstrate the features that may indicate a dynamic coupling between even-frequency condensates and odd-frequency gapless superconducting condensates.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"21 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. I. Bondarenko, V. P. Timofeev, V. P. Koverya, A. V. Krevsun
Information on the state of research on the effect of hydrogen on the superconducting properties of various compounds is presented. The review consists of an introduction, one appendix and four sections: methods for the synthesis of modern hydrogen-containing superconductors, experimental studies of the properties of hydrogen-containing superconductors, mechanisms of the influence of hydrogen on superconductivity, problems and prospects of hydrogen-containing superconductors.
{"title":"Hydrogen in superconductors (Review article)","authors":"S. I. Bondarenko, V. P. Timofeev, V. P. Koverya, A. V. Krevsun","doi":"10.1063/10.0027919","DOIUrl":"https://doi.org/10.1063/10.0027919","url":null,"abstract":"Information on the state of research on the effect of hydrogen on the superconducting properties of various compounds is presented. The review consists of an introduction, one appendix and four sections: methods for the synthesis of modern hydrogen-containing superconductors, experimental studies of the properties of hydrogen-containing superconductors, mechanisms of the influence of hydrogen on superconductivity, problems and prospects of hydrogen-containing superconductors.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"102 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Menesenko, O. Feia, A. Shapovalov, V. Tarenkov, I. Gavrysh, E. Zhitlukhina, M. Belogolovskii, A. Parra, A. Aliev
We present the first point-contact measurements of heavily reduced indium tin oxide (ITO) films in the superconducting state, which simultaneously demonstrate high transparency in the visible light spectrum. Analysis of the differential conductance spectrum indicates the presence of two superconducting phases, the main one with a critical temperature Tc of about 4.6 K and an additional phase with Tc ∼ 10 K, most likely localized near the surface. The phase separation is indirectly confirmed by resistance measurements of the layers and ab initio calculations of the doped ITO electronic structure. The results obtained give hope for the creation of transparent superconducting films with critical temperatures of about 10 K.
我们首次对处于超导状态的重度还原氧化铟锡（ITO）薄膜进行了点接触测量，测量结果同时显示了其在可见光光谱下的高透明度。对微分电导谱的分析表明存在两个超导相，主要超导相的临界温度 Tc 约为 4.6 K，另一个超导相的临界温度 Tc ～ 10 K，很可能位于表面附近。层电阻测量和掺杂 ITO 电子结构的 ab initio 计算间接证实了相分离。这些结果为创造临界温度约为 10 K 的透明超导薄膜带来了希望。
{"title":"Two-phase/two-gap scenario in heavily reduced superconducting ITO films revealed by point-contact spectroscopy","authors":"D. Menesenko, O. Feia, A. Shapovalov, V. Tarenkov, I. Gavrysh, E. Zhitlukhina, M. Belogolovskii, A. Parra, A. Aliev","doi":"10.1063/10.0027926","DOIUrl":"https://doi.org/10.1063/10.0027926","url":null,"abstract":"We present the first point-contact measurements of heavily reduced indium tin oxide (ITO) films in the superconducting state, which simultaneously demonstrate high transparency in the visible light spectrum. Analysis of the differential conductance spectrum indicates the presence of two superconducting phases, the main one with a critical temperature Tc of about 4.6 K and an additional phase with Tc ∼ 10 K, most likely localized near the surface. The phase separation is indirectly confirmed by resistance measurements of the layers and ab initio calculations of the doped ITO electronic structure. The results obtained give hope for the creation of transparent superconducting films with critical temperatures of about 10 K.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"163 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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