{"title":"零外加场中FeSe0.5Te0.5超导刚度和相干长度的测量","authors":"Amotz Peri, I. Mangel, A. Keren","doi":"10.3390/condmat8020039","DOIUrl":null,"url":null,"abstract":"Superconducting stiffness ρs and coherence length ξ are usually determined by measuring the penetration depth λ of a magnetic field and the upper critical field Hc2 of a superconductor (SC), respectively. However, in magnetic SC, which is iron-based, this could lead to erroneous results, since the internal field could be very different from the applied one. To overcome this problem in Fe1+ySexTe1−x with x∼0.5 and y∼0 (FST), we measured both quantities with the Stiffnessometer technique. In this technique, one applies a rotor-free vector potential A to a superconducting ring and measures the current density j via the ring’s magnetic moment m. ρs and ξ are determined from London’s equation, j=−ρsA, and its range of validity. This method is particularly accurate at temperatures close to the critical temperature Tc. We find weaker ρs and longer ξ than existing literature reports, and critical exponents which agree better with expectations based on the Ginzburg–Landau theory.","PeriodicalId":10665,"journal":{"name":"Condensed Matter","volume":" ","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2023-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Superconducting Stiffness and Coherence Length of FeSe0.5Te0.5 Measured in a Zero-Applied Field\",\"authors\":\"Amotz Peri, I. Mangel, A. Keren\",\"doi\":\"10.3390/condmat8020039\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Superconducting stiffness ρs and coherence length ξ are usually determined by measuring the penetration depth λ of a magnetic field and the upper critical field Hc2 of a superconductor (SC), respectively. However, in magnetic SC, which is iron-based, this could lead to erroneous results, since the internal field could be very different from the applied one. To overcome this problem in Fe1+ySexTe1−x with x∼0.5 and y∼0 (FST), we measured both quantities with the Stiffnessometer technique. In this technique, one applies a rotor-free vector potential A to a superconducting ring and measures the current density j via the ring’s magnetic moment m. ρs and ξ are determined from London’s equation, j=−ρsA, and its range of validity. This method is particularly accurate at temperatures close to the critical temperature Tc. We find weaker ρs and longer ξ than existing literature reports, and critical exponents which agree better with expectations based on the Ginzburg–Landau theory.\",\"PeriodicalId\":10665,\"journal\":{\"name\":\"Condensed Matter\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2023-04-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Condensed Matter\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3390/condmat8020039\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"PHYSICS, CONDENSED MATTER\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Condensed Matter","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/condmat8020039","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
Superconducting Stiffness and Coherence Length of FeSe0.5Te0.5 Measured in a Zero-Applied Field
Superconducting stiffness ρs and coherence length ξ are usually determined by measuring the penetration depth λ of a magnetic field and the upper critical field Hc2 of a superconductor (SC), respectively. However, in magnetic SC, which is iron-based, this could lead to erroneous results, since the internal field could be very different from the applied one. To overcome this problem in Fe1+ySexTe1−x with x∼0.5 and y∼0 (FST), we measured both quantities with the Stiffnessometer technique. In this technique, one applies a rotor-free vector potential A to a superconducting ring and measures the current density j via the ring’s magnetic moment m. ρs and ξ are determined from London’s equation, j=−ρsA, and its range of validity. This method is particularly accurate at temperatures close to the critical temperature Tc. We find weaker ρs and longer ξ than existing literature reports, and critical exponents which agree better with expectations based on the Ginzburg–Landau theory.