Local Heating in a Normal-Metal-Quantum-Dot-Superconductor System without Electric Voltage Bias

作     者：周利玲 周雪云 程融 侯翠岭 沈红 

作者机构：Department of Physics Jiujiang University Jiujiang 332005 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2017年第34卷第6期

页      面：79-83页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Supported by the National Natural Science Foundation of China under Grant No 11164011 

主　　题：Semiconductor quantum dots 

摘      要：We investigate the heat generation Q in a quantum dot （QD）, coupled to a normal metal and a superconduc- tor, without electric bias voltage. It is found that Q is quite sensitive to the lead temperatures TL,R and the superconductor gap magnitude △. At TL,R 〈〈 ω0 （ω0 is the phonon frequency）, the superconductor affects Q only at △ 〈ω0, and the maximum magnitude of negative Q appears at some △ slightly smaller than ω0. At elevated lead temperature, contribution to O from the superconductor arises at △, ranging from less than to much larger than wo. However, the peak value of Q is several times smaller than that in the case of TL,R 〈〈ω0. Interchanging lead temperatures TL and TR leads to quite different Q behaviors, while this makes no difference for a normal-metal quantum-dot-normal-metal system, and the QD can be cooled much more efficiently when the superconductor is colder.