{"title":"在还原钽酸钾中观察到高达 8.7 K 的超导电性","authors":"Xueshan Cao, Zhongran Liu, Jiayi Lu, Wenze Pan, Yishuai Wang, Yuexin Shi, Siyuan Hong, Ming Qin, Guanghan Cao, Meng Zhang, He Tian, Yanwu Xie","doi":"10.1002/qute.202400255","DOIUrl":null,"url":null,"abstract":"<p>The observation of superconductivity with a transition temperature (<i>T</i><sub>c</sub>) up to 8.7 K in KTaO<sub>3</sub> single crystals annealed with CaH<sub>2</sub> at 900–1000 °C is reported. The superconductivity is confirmed by both resistance and magnetization measurements and is 3D in nature. Characterizations of X-ray photoelectron spectroscopy, X-ray diffraction, and scanning transmission electron microscopy reveal that it locates in a 1-µm-order-thick polycrystalline surface layer that shows a rock-salt type structure, with a lattice constant of 0.454 nm, and can be chemically identified as K<i><sub>x</sub></i>TaO<i><sub>y</sub></i> (0.04 ≤ <i>x</i> ≤ 0.08, 1.24 ≤ <i>y</i> ≤ 1.35), depending on annealing conditions. Within the experimental ranges, the <i>T</i><sub>c</sub> is peaked at <i>x</i> ≈0.05, and increases with decreasing <i>y</i>, and the highest <i>T</i><sub>c</sub> is observed in K<sub>0.05</sub>TaO<sub>1.24</sub>. The <i>T</i><sub>c</sub> observed here is much higher than that of KTaO<sub>3</sub>, Ta, and pure TaO, and is also one of the highest among of all the known oxide superconductors with the same rock-salt structure. The rather high <i>T</i><sub>c</sub> and its close connection with KTaO<sub>3</sub> and Ta, both of which are promising materials for quantum computing, make K<i><sub>x</sub></i>TaO<i><sub>y</sub></i> potentially interesting as a building block in constructing future superconducting quantum devices.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 8","pages":""},"PeriodicalIF":4.4000,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Observation of Superconductivity Up to 8.7 K in Reduced Potassium Tantalate\",\"authors\":\"Xueshan Cao, Zhongran Liu, Jiayi Lu, Wenze Pan, Yishuai Wang, Yuexin Shi, Siyuan Hong, Ming Qin, Guanghan Cao, Meng Zhang, He Tian, Yanwu Xie\",\"doi\":\"10.1002/qute.202400255\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The observation of superconductivity with a transition temperature (<i>T</i><sub>c</sub>) up to 8.7 K in KTaO<sub>3</sub> single crystals annealed with CaH<sub>2</sub> at 900–1000 °C is reported. The superconductivity is confirmed by both resistance and magnetization measurements and is 3D in nature. Characterizations of X-ray photoelectron spectroscopy, X-ray diffraction, and scanning transmission electron microscopy reveal that it locates in a 1-µm-order-thick polycrystalline surface layer that shows a rock-salt type structure, with a lattice constant of 0.454 nm, and can be chemically identified as K<i><sub>x</sub></i>TaO<i><sub>y</sub></i> (0.04 ≤ <i>x</i> ≤ 0.08, 1.24 ≤ <i>y</i> ≤ 1.35), depending on annealing conditions. Within the experimental ranges, the <i>T</i><sub>c</sub> is peaked at <i>x</i> ≈0.05, and increases with decreasing <i>y</i>, and the highest <i>T</i><sub>c</sub> is observed in K<sub>0.05</sub>TaO<sub>1.24</sub>. The <i>T</i><sub>c</sub> observed here is much higher than that of KTaO<sub>3</sub>, Ta, and pure TaO, and is also one of the highest among of all the known oxide superconductors with the same rock-salt structure. The rather high <i>T</i><sub>c</sub> and its close connection with KTaO<sub>3</sub> and Ta, both of which are promising materials for quantum computing, make K<i><sub>x</sub></i>TaO<i><sub>y</sub></i> potentially interesting as a building block in constructing future superconducting quantum devices.</p>\",\"PeriodicalId\":72073,\"journal\":{\"name\":\"Advanced quantum technologies\",\"volume\":\"7 8\",\"pages\":\"\"},\"PeriodicalIF\":4.4000,\"publicationDate\":\"2024-06-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advanced quantum technologies\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/qute.202400255\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"OPTICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced quantum technologies","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/qute.202400255","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
摘要
据报道,在 900-1000 °C 下用 CaH2 退火的 KTaO3 单晶体中观察到了过渡温度 (Tc) 高达 8.7 K 的超导现象。这种超导电性通过电阻和磁化测量得到证实,并且具有三维性质。X 射线光电子能谱、X 射线衍射和扫描透射电子显微镜的特性分析表明,超导位于 1 微米厚的多晶体表层,该表层显示出岩石-盐类结构,晶格常数为 0.454 纳米,根据退火条件的不同,可将其化学鉴定为 KxTaOy(0.04 ≤ x ≤ 0.08,1.24 ≤ y ≤ 1.35)。在实验范围内,Tc 在 x ≈0.05 时达到峰值,并随着 y 的减小而增大,K0.05TaO1.24 的 Tc 最高。这里观察到的 Tc 远高于 KTaO3、Ta 和纯 TaO,也是具有相同岩盐结构的所有已知氧化物超导体中最高的之一。KxTaOy 具有相当高的 Tc 值,而且与 KTaO3 和 Ta 关系密切,这两种材料都是量子计算的理想材料,因此 KxTaOy 有可能成为构建未来超导量子设备的构件。
Observation of Superconductivity Up to 8.7 K in Reduced Potassium Tantalate
The observation of superconductivity with a transition temperature (Tc) up to 8.7 K in KTaO3 single crystals annealed with CaH2 at 900–1000 °C is reported. The superconductivity is confirmed by both resistance and magnetization measurements and is 3D in nature. Characterizations of X-ray photoelectron spectroscopy, X-ray diffraction, and scanning transmission electron microscopy reveal that it locates in a 1-µm-order-thick polycrystalline surface layer that shows a rock-salt type structure, with a lattice constant of 0.454 nm, and can be chemically identified as KxTaOy (0.04 ≤ x ≤ 0.08, 1.24 ≤ y ≤ 1.35), depending on annealing conditions. Within the experimental ranges, the Tc is peaked at x ≈0.05, and increases with decreasing y, and the highest Tc is observed in K0.05TaO1.24. The Tc observed here is much higher than that of KTaO3, Ta, and pure TaO, and is also one of the highest among of all the known oxide superconductors with the same rock-salt structure. The rather high Tc and its close connection with KTaO3 and Ta, both of which are promising materials for quantum computing, make KxTaOy potentially interesting as a building block in constructing future superconducting quantum devices.