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

• 作 者: Fu-Li Sun Yuan-Dong Wang Jian-Hua Wei Yi-Jing Yan
• 机 构: Department of Physics&Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano D
• 出 处: 中国物理B（英文版）
• 发表日期: 2020年6期
• 关键词: Kondo effect Fano effect quantum dot capacitive coupling

We report capacitive coupling induced Kondo–Fano (K–F) interference in a double quantum dot (DQD) by systemati-cally 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 shiftη(ω) is suitable for analysis of the Kondo–Fano interference. We present a general approach for calculatingη(ω) and applying it to the DQD in the K–F regime where the two maxima ofη(ω=0) characterize the interferences between the Kondo resonance state and S-O2 and S-O1 substates, respectively.