Novel transport phenomena in spin-triplet superconductor

自旋三重态超导体中的新颖输运现象

• 批准号: 21740276
• 负责人: KAMBARA Hiroshi
• 金额: $ 2.91万
• 依托单位: Shinshu University (2010)National Institute of Advanced Industrial Science and Technology (2009)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21740276/
• 关键词: 強相関系; スピン3重項超伝導; ルテニウム酸化物; カイラルp波超伝導; Sr_2RuO_4; トンネルスペクトル; ブレークジャンクション; スピン2重項超伝導; Sr_2RuO_4-Ru共晶系; 超伝導接合; カイラルドメイン

Using micro fabrication techniques, we investigated local transport characteristics of spin-triplet p-wave superconductor Sr_2RuO_4 (SRO). We observed novel phenomena such as, (i) an unconventional hysteresis in voltage-current characteristics in a few μm-width weak junction, and (ii) a large enhancement of superconducting critical current density with reducing cross section below 100m^2. These phenomena imply that edge states are formed in a microfabricated SRO device. We also studied tunnel spectra of an SRO break junction formed by microfabrication. The tunnel spectra showed broad zero-bias conductance peaks, which supports the chiral p-wave state in SRO.

利用微加工技术研究了自旋三重态p波超导体Sr_2RuO_4（SRO）的局域输运特性。我们观察到了一些新的现象，例如：（i）在几μ m宽的弱结中，电压-电流特性出现了非常规的滞后现象;（ii）在小于100 m^2的截面减小时，超导临界电流密度大大增强。这些现象意味着边缘态形成在微制造的SRO器件中。我们还研究了微加工形成的SRO断裂结的隧道谱。隧道谱显示了宽的零偏压电导峰，这支持了SRO中的手征p波态。