基于双晶退火衬底的高温超导纳米量子干涉仪在液氦液氮温区下的输运特性  

Transport Properties of High-Temperature Nano Superconducting Quantum Interference Devices based on Biocrystal Annealed Substrates in Liquid Helium and Liquid Nitrogen

作　　者：秦晟昊 张昊晖 吴瑶 周晗 黄一聪 林建新 QIN Shenghao;ZHANG Haohui;WU Yao;ZHOU Han;HUANG Yicong;LIN Jianxin(Qingdao Innovation and Development Center of Harbin Engineering University,Qingdao 266404,China;College of Intelligent Systems Science and Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]青岛哈尔滨工程大学创新发展中心,青岛266404 [2]哈尔滨工程大学,智能科学与工程学院,哈尔滨150001

出　　处：《低温物理学报》2023年第6期330-336,共7页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:12104112);山东省自然科学基金(批准号:ZR2021QA036);中央高校基本科研业务费专项资金(批准号:3072022TS2602)资助的课题。

摘　　要：超导纳米量子干涉器件是近年来发展起来的一种新型超导器件,通过现代微纳加工技术将其超导环缩小到纳米尺寸,构成高度灵敏的微观自旋探测器,理论上可以达到测量单电子自旋的灵敏度.同时,高温超导由于具有较高的临界温度和上临界场也备受关注.然而,相比于低温超导量子干涉器件,高温超导量子干涉器件的1/f噪声更加显著,这限制了其在低频下的应用.本文基于双晶衬底技术,通过聚焦离子束加工制备高温超导纳米量子干涉仪,并对其在液氦和液氮温区下的电学性能、4.2 K下的磁通噪声进行表征.实验发现,通过预先退火处理钛酸锶双晶衬底,可以有效改善衬底表面的粗糙度,进而优化高温超导纳米量子干涉仪的1/f磁通噪声.最终得到低频下(1 Hz)的磁通噪声灵敏度为4.9μΦ_(0)/Hz^(1/2),比未事先预处理的小一到两个数量级,这对于推进高温超导纳米量子干涉器件在低频下的应用意义重大.The nano superconducting quantum interference device is anew type of superconducting device developed in recent years,which minimizes its superconducting loop size to nanoscale by modern micro-nano fabrication technology to constitute a highly sensitive microscopbic spin detector.Theoretically,it can reach the sensitivity of being able to measure single-electron spins.Meanwhile,high-temperature superconductivity has attracted much attention due to its high critical temperature and ujper critical field.However,compared with low temperature superconducting quantum interference devices,high-temperature superconducting quantum interference devices have more significant 1/f noise,which limits their applications at low frequencies.In this paper,high temperature nano superconducting quantum interference devices areprepared by focused-ion-beam milling based on bicrystal substrate technology,and the electrical properties(in tlhe temperature range of liquid helium and liquid nitrogen)andfluxnoise(atT=4.2K)havebeenchavebeen characterized.We found that pre-annealing the SiTrO3 bicrystal substrate improves surface roughness.This optimization reducesthe 1/f flux noise of the high-temperature nano superconducting quantum interference devices,and finally obtainsa flux noise sensitivity of 4.9μΦ_(0)/Hz^(1/2) at low frequency(1Hz),which is one to two orders of magnitude better than without pre-processing.This advancement is significant for advancing the application of high-temperature nanosuperconducting quantum interference devices at low frequency.

关 键 词：超导器件 高温超导薄膜 超导量子干涉器件 

分 类 号：O469[理学—凝聚态物理]