Photon-assistant Fano resonance in serially coupled triple quantum dots

• Published in: Journal of physics. Condensed matter 2008-08, Vol.20 (32), p.325223-325223 (5), Article 325223
• Main Authors: Xie, Wanyuan, Chu, Weidong, Zhang, Wei, Duan, Suqing
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Physics; Quantum dots
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/20/32/325223

Based on calculations of the electronic structure of serially coupled triple quantum dots (left, middle, right dots) (STQDs), we study the transport properties of the system driven by an ac electric field. It is found that the Lambda-type energy level of STQDs has great impact on the transport properties. For an asymmetric (between left and right dots) configuration, there is a symmetric peak in the current-AC frequency curve due to resonant photon induced mixing between the left/right dot and the middle dot. In the symmetric (between left and right dots) configuration, a Fano asymmetric line shape appears in the current-frequency curve with the help of a 'trapping dark state'. Here the interesting coherent trapping phenomena, which usual appear in quantum optics, play an essential role in quantum electronic transport. We provide a clear physics picture for the Fano resonance and convenient ways to tune the Fano effects.