当前位置: X-MOL 学术J. Exp. Theor. Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The Josephson Effect in PbIn/Fe 1 – y Se 1 – x Te x Point Contacts: Probing the Order Parameter Symmetry
Journal of Experimental and Theoretical Physics ( IF 1.0 ) Pub Date : 2020-04-01 , DOI: 10.1134/s1063776120020156
V. A. Stepanov , M. V. Golubkov

Abstract

Characteristics of the Josephson effect in Pb0.6In0.4/FeSe0.4Te0.6 point contacts with the current flowing parallel to ab plane of the iron chalcogenide crystal (with critical temperature Tc ≈ 15 K) have been studied. Dependences of the critical current Ic and amplitudes In of the first steps of current (Shapiro steps) in the current–voltage (IV) characteristics (n = 0, 1, 2; I0 = Ic) on the microwave power P (at frequency f = 7.6 GHz) and dependences of the characteristic voltage Vc(T) = IcRN (RN being the normal state resistance) on the temperature T have been measured. It is found that the characteristics of contacts (Ic, RN, Vc) obtained for initial parts of the IV curves do not adequately describe the oscillations of current steps in the microwave radiation field. A method is proposed for determining the normalized microwave frequency Ω = 2πf(2eVc/\(\hbar \))–1 that provides quantitative description of the current oscillation steps in the framework of a resistive contact model and allows one to check that the Josephson superconducting current Is is proportional to sin(aφ) (a = 1, 2), where φ is the phase difference of the order parameters. Comparison of the measured In(\(\sqrt P \)) curves to those calculated using the resistive model showed that Is = Icsinφ, in agreement with the conventional s and s++ symmetry of the order parameter in FeSe0.4Te0.6. It is established that Vc of the contacts studied is proportional to T in a wide temperature interval.


中文翻译:

PbIn / Fe 1 – y Se 1 – x Te x点接触中的约瑟夫森效应:探测阶次参数对称性

摘要

在铅的约瑟夫逊效应特性0.60.4 / FESE 0.40.6与电流流动平行于点接触AB的铁硫族化物晶体的平面(与临界温度Ť Ç ≈15 K)进行了研究。的临界电流的依赖性Ç和振幅Ñ的在电流-电压的电流(夏皮罗步骤)第一步骤(- V)特性(Ñ ; = 0,1,20 =Ç对微波)功率P(在频率f= 7.6GHz下)和特征电压V cT)=I c R NR N为常态电阻)对温度T的依赖性已被测量。结果发现接触的特性(Ç- [R ÑV Ç为的初始部分而获得)- V曲线不充分地描述的在微波辐射场电流的步骤的振荡。提出了确定归一化微波频率Ω=2π的方法f(2 eV c / \(\ hbar \))– 1提供电阻性接触模型框架中电流振荡步骤的定量描述,并允许人们检查约瑟夫森超导电流I s与sin(a φ)(a  = 1,2),其中φ是阶数参数的相位差。所测量的比较Ñ\(\ SQRT P \) )曲线的那些使用计算出的电阻模型表明,小号=Ç sinφ,与传统协议小号小号FeSe 0.4 Te 0.6中有序参数的++对称性。已经确定,V Ç研究的触点的正比于Ť在较宽的温度间隔。
更新日期:2020-04-01
down
wechat
bug