InN超导中的磁通钉扎性质研究  

Flux pinning properties of InN

作　　者：宋志勇[1,2,4] 商丽燕 陈平平[2] 褚君浩[1,2] AKIO Yamamoto[3] 康亭亭 SONG Zhi-Yong;SHANG Li-Yan;CHU Jun-Hao;CHEN Ping-Ping;Akio Yamamoto;KANG Ting-Ting(East China Normal University,Shanghai 200062,China;State Key Laboratory of Infrared Physics,Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;University of Fukui,Fukui,910-8507,Japan;Key Laboratory of Nanodevices and Applications,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China)

机构地区：[1]华东师范大学通信与电子工程学院,上海200062 [2]中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083 [3]University of Fukui,Fukui 910-8507,Japan [4]中国科学院纳米器件与应用重点实验室,江苏苏州215123

出　　处：《红外与毫米波学报》2021年第3期321-328,共8页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金(11204334,61475178)。

摘　　要：InN是三五族半导体中唯一具有超导性质的材料,在超导体/半导体混合器件领域具有重要的应用价值。运用磁输运的方法,系统性地研究了磁通钉扎对InN超导性质的影响。通过对超导转变过程中的Ⅰ-Ⅴ曲线进行标度,发现InN超导中存在涡旋液体态到涡旋玻璃态的相变。在涡旋液体态,用热激活磁通蠕动模型分析了磁通运动的机制,发现InN超导中存在单磁通钉扎到集体钉扎的转变;在涡旋玻璃态,首先对临界电流与温度的关系进行了分析,确定了InN超导中主要的磁通钉扎机制:δL钉扎。然后对临界电流与磁场的关系进行了分析,发现临界电流在磁场下的迅速衰减是集体钉扎所导致的结果。最后,基于Dew-Hughes模型,对钉扎力与磁场强度的依赖关系进行了分析,发现InN中的钉扎中心的主要是点钉扎。该研究为提高InN的临界电流密度奠定基础。The superconductivity in InN is the foundation for the all Ⅲ-Ⅴ semiconductor based superconductor/semiconductor integration. To study the flux pinning properties of InN superconductor,the Ⅰ-Ⅴ relationships,R-B transitions,and R-T transitions are investigated. The scaling results of Ⅰ-Ⅴ curves indicate there is a vortex glass-liquid transition.The R-T curves are well fitted by thermally activated flux flow(TAFF)model. The TAFF activated energy satisfies a power-law relationship with magnetic field,but it has two different exponents under the low magnetic field and high magnetic field. We explain it as the result of a transition from single flux pinning to collective flux pinning which also leads to the rapid attenuation of critical current as the magnetic field increases. By analyzing the temperature dependence of critical current,we found the dominant δL-pinning mechanism. Furthermore,the dependence of pinning force on magnetic field is analyzed using the Dew-Hughes model,and the results show that the main pinning center is the point pinning. Our work paves the way for studying Ⅲ-nitrides based hybrid superconductor-semiconductor devices.

关 键 词：氮化铟 超导 磁通动力学 钉扎机制 临界电流 

分 类 号：O472[理学—半导体物理] O469[理学—物理]