Probing the minigap in topological insulator-based Josephson junctions under radio frequency irradiation  

作　　者：Guang Yang Zhaozheng Lyu Xiang Zhang Fanming Qu Li Lu 杨光;吕昭征;张祥;屈凡明;吕力(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Songshan Lake Materials Laboratory Dongguan 523808,China;CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [3]Songshan Lake Materials Laboratory Dongguan 523808,China [4]CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China [5]Beijing Academy of Quantum Information Sciences,Beijing 100193,China

出　　处：《Chinese Physics B》2019年第12期52-55,共4页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China(Grant Nos.2016YFA0300601,2017YFA0304700,and 2015CB921402);the National Natural Science Foundation China(Grant Nos.11527806,91221203,11174357,91421303,and 11774405);the Strategic Priority Research Program B of the Chinese Academy of Sciences(Grant Nos.XDB07010100 and XDB28000000);the Beijing Municipal Science&Technology Commission,China(Grant No.Z191100007219008)

摘　　要：Recently,a contact-resistance-measurement method was developed to detect the minigap,hence the Andreev bound states(ABSs),in Josephson junctions constructed on the surface of three-dimensional topological insulators(3D TIs).In this work,we further generalize that method to the circumstance with radio frequency(rf)irradiation.We find that with the increase of the rf power,the measured minigap becomes broadened and extends to higher energies in a way similar to the rf power dependence of the outer border of the Shapiro step region.We show that the corresponding data of contact resistance under rf irradiation can be well interpreted by using the resistively shunted Josephson junction(RSJ)model and the Blonder–Tinkham–Klapwijk(BTK)theory.Our findings could be useful when using the contact-resistancemeasurement method to study the Majorana-related physics in topological insulator-based Josephson junctions under rf irradiation.Recently, a contact-resistance-measurement method was developed to detect the minigap, hence the Andreev bound states(ABSs), in Josephson junctions constructed on the surface of three-dimensional topological insulators(3D TIs).In this work, we further generalize that method to the circumstance with radio frequency(rf) irradiation. We find that with the increase of the rf power, the measured minigap becomes broadened and extends to higher energies in a way similar to the rf power dependence of the outer border of the Shapiro step region. We show that the corresponding data of contact resistance under rf irradiation can be well interpreted by using the resistively shunted Josephson junction(RSJ)model and the Blonder–Tinkham–Klapwijk(BTK) theory. Our findings could be useful when using the contact-resistancemeasurement method to study the Majorana-related physics in topological insulator-based Josephson junctions under rf irradiation.

关 键 词：topological insulator Josephson junction contact-resistance-measurement method radio frequency irradiation 

分 类 号：O51[理学—低温物理]