中国物理B ›› 2020, Vol. 29 ›› Issue (6): 67204-067204.doi: 10.1088/1674-1056/ab8ac1

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Capacitive coupling induced Kondo-Fano interference in side-coupled double quantum dots

Fu-Li Sun(孙复莉), Yuan-Dong Wang(王援东), Jian-Hua Wei(魏建华), Yi-Jing Yan(严以京)   

  1. 1 Department of Physics & Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China;
    2 Hefei National Laboratory for Physical Sciences at the Microscale & Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2020-02-21 修回日期:2020-04-17 出版日期:2020-06-05 发布日期:2020-06-05
  • 通讯作者: Jian-Hua Wei E-mail:wjh@ruc.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11774418, 11374363, and 21373191).

Capacitive coupling induced Kondo-Fano interference in side-coupled double quantum dots

Fu-Li Sun(孙复莉)1, Yuan-Dong Wang(王援东)1, Jian-Hua Wei(魏建华)1, Yi-Jing Yan(严以京)2   

  1. 1 Department of Physics & Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China;
    2 Hefei National Laboratory for Physical Sciences at the Microscale & Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
  • Received:2020-02-21 Revised:2020-04-17 Online:2020-06-05 Published:2020-06-05
  • Contact: Jian-Hua Wei E-mail:wjh@ruc.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11774418, 11374363, and 21373191).

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摘要： We report capacitive coupling induced Kondo-Fano (K-F) interference in a double quantum dot (DQD) by systematically investigating its low-temperature properties on the basis of hierarchical equations of motion evaluations. We show that the interdot capacitive coupling U12 splits the singly-occupied (S-O) state in quantum dot 1 (QD1) into three quasi-particle substates: the unshifted S-O0 substate, and elevated S-O1 and S-O2. As U12 increases, S-O2 and S-O1 successively cross through the Kondo resonance state at the Fermi level (ω=0), resulting in the so-called Kondo-I (KI), K-F, and Kondo-II (KII) regimes. While both the KI and KII regimes have the conventional Kondo resonance properties, remarkable Kondo-Fano interference features are shown in the K-F regime. In the view of scattering, we propose that the phase shift η(ω) is suitable for analysis of the Kondo-Fano interference. We present a general approach for calculating η(ω) and applying it to the DQD in the K-F regime where the two maxima of η(ω=0) characterize the interferences between the Kondo resonance state and S-O2 and S-O1 substates, respectively.

关键词: Kondo effect, Fano effect, quantum dot, capacitive coupling

Abstract: We report capacitive coupling induced Kondo-Fano (K-F) interference in a double quantum dot (DQD) by systematically investigating its low-temperature properties on the basis of hierarchical equations of motion evaluations. We show that the interdot capacitive coupling U12 splits the singly-occupied (S-O) state in quantum dot 1 (QD1) into three quasi-particle substates: the unshifted S-O0 substate, and elevated S-O1 and S-O2. As U12 increases, S-O2 and S-O1 successively cross through the Kondo resonance state at the Fermi level (ω=0), resulting in the so-called Kondo-I (KI), K-F, and Kondo-II (KII) regimes. While both the KI and KII regimes have the conventional Kondo resonance properties, remarkable Kondo-Fano interference features are shown in the K-F regime. In the view of scattering, we propose that the phase shift η(ω) is suitable for analysis of the Kondo-Fano interference. We present a general approach for calculating η(ω) and applying it to the DQD in the K-F regime where the two maxima of η(ω=0) characterize the interferences between the Kondo resonance state and S-O2 and S-O1 substates, respectively.

Key words: Kondo effect, Fano effect, quantum dot, capacitive coupling

中图分类号:  (Scattering mechanisms and Kondo effect)

  • 72.15.Qm
73.63.Kv (Quantum dots) 75.20.Hr (Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions)