Multicomponent superconductors exhibit nontrivial vortex behaviors due to the various vortex–vortex interactions,including the competing one in the recently proposed type-1.5 superconductor.However,potential candidat...Multicomponent superconductors exhibit nontrivial vortex behaviors due to the various vortex–vortex interactions,including the competing one in the recently proposed type-1.5 superconductor.However,potential candidate that can be used to study the multicomponent superconductivity is rare.Here,we prepared an artificial superconducting multilayer to act as an alternative approach to study multicomponent superconductivity.The additional repulsive length and the coupling strength among superconducting films were regulated by changing the thickness of the insulting layer.The magnetization measurements were performed to clarify the effect of the competition between the repulsive vortex interactions on the macroscopic superconductivity.The vortex phase diagram and the optimum critical current density have been determined.Furthermore,a second magnetization effect is observed,and is attributed to the upper layer,which provides the weak pinning sites to localize the flux lines.The pinning behaviors switches to the mixed type with the increase of the insulting layer thicknesses.Our results open a new perspective to the study and related applications of the multilayer superconducting systems.展开更多
Recent studies proposed the two-band effect and the related type-1.5 superconductivity in Zr B12single crystal.Here,by combining both macroscopic and microscopic measurements,the superconducting properties and the int...Recent studies proposed the two-band effect and the related type-1.5 superconductivity in Zr B12single crystal.Here,by combining both macroscopic and microscopic measurements,the superconducting properties and the intricate vortex matter of Zr B12are studied in detail.The vortex phase diagram is constructed,where the temperature dependence of the upper critical field can be well reproduced using a two-band Werthamer-Helfand-Hohenberg(WHH)model.A pronounced surface superconductivity is also found in the same temperature range,where the semi-Meissner state is observed.Both phenomena are attributed to the weakly coupled two-band effect.The direct visualization of the semi-Meissner state exhibits an inhomogeneous distribution of vortex clusters,vortex chains and large Meissner areas.With the increase of magnetic field,a transition from the semi-Meissner state to the mixed state is revealed and further supported by statistical analysis of the vortex pattern.Our results provide direct experimental evidence for the type-1.5 superconductivity in ZrB_(12).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12174242)the National Key Research and Development Program of China (Grant No. 2018YFA0704300)+1 种基金the Key Research Project of Zhejiang Laboratory (Grant No. 2021PE0AC02)the support by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning
文摘Multicomponent superconductors exhibit nontrivial vortex behaviors due to the various vortex–vortex interactions,including the competing one in the recently proposed type-1.5 superconductor.However,potential candidate that can be used to study the multicomponent superconductivity is rare.Here,we prepared an artificial superconducting multilayer to act as an alternative approach to study multicomponent superconductivity.The additional repulsive length and the coupling strength among superconducting films were regulated by changing the thickness of the insulting layer.The magnetization measurements were performed to clarify the effect of the competition between the repulsive vortex interactions on the macroscopic superconductivity.The vortex phase diagram and the optimum critical current density have been determined.Furthermore,a second magnetization effect is observed,and is attributed to the upper layer,which provides the weak pinning sites to localize the flux lines.The pinning behaviors switches to the mixed type with the increase of the insulting layer thicknesses.Our results open a new perspective to the study and related applications of the multilayer superconducting systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174242,and 11804217)the National Key Research and Development Program of China(Grant No.2018YFA0704300)+1 种基金the Key Research Project of Zhejiang Laboratory(Grant No.2021PE0AC02)the support by the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Recent studies proposed the two-band effect and the related type-1.5 superconductivity in Zr B12single crystal.Here,by combining both macroscopic and microscopic measurements,the superconducting properties and the intricate vortex matter of Zr B12are studied in detail.The vortex phase diagram is constructed,where the temperature dependence of the upper critical field can be well reproduced using a two-band Werthamer-Helfand-Hohenberg(WHH)model.A pronounced surface superconductivity is also found in the same temperature range,where the semi-Meissner state is observed.Both phenomena are attributed to the weakly coupled two-band effect.The direct visualization of the semi-Meissner state exhibits an inhomogeneous distribution of vortex clusters,vortex chains and large Meissner areas.With the increase of magnetic field,a transition from the semi-Meissner state to the mixed state is revealed and further supported by statistical analysis of the vortex pattern.Our results provide direct experimental evidence for the type-1.5 superconductivity in ZrB_(12).
