Single plasmon routing with the four quantum dots coupled to a cross-type plasmonic waveguide

• Published in: Quantum information processing 2023-05, Vol.22 (6), Article 226
• Main Authors: Kim, Chol-Min, Kim, Nam-Chol, Ko, Myong-Chol, Ryom, Ju-Song, Choe, Hyok-Chol
• Format: Article
• Language: English
• Subjects: Data Structures and Information Theory; Mathematical Physics; Physics; Physics and Astronomy; Quantum Computing; Quantum Information Technology; Quantum Physics; Spintronics
• ISSN: 1573-1332; 1573-1332
• DOI: 10.1007/s11128-023-03976-5

We proposed a new scheme of multichannel quantum routing for single plasmons (SPs) using the cross-type plasmonic waveguides (PWs) that couples to four two-level InGaAs quantum dots (QDs). In our proposed system, each of two PWs in cross type can be infinite silver nanowire. We theoretically studied the routing properties of the proposed system for the incident SPs by using the real-space formalism. Our results show that in such a coupled system, the routing of incident SPs can be achieved depending on several physical parameters, such as the detuning of the transition frequencies of QDs from the frequency of propagating SPs, the coupling strengths of the QDs to PWs and the separation distance between the QDs. It is shown that the transmission of SPs can be switched on or off by adjusting the separation distance between the QDs, which could be exploited to probe the spacing between the QDs. It is also shown that the transfer rate of SPs can be switchable and redirected by appropriately adjusting the QDs’ separation distance and coupling strengths, which is a prerequisite for quantum routers. Our multichannel scheme for the routing of the SPs could be utilized for making quantum devices realizable, such as quantum routers, quantum filters, directional couplers and quantum switches.