Double-Fano resonance in a two-level quantum system coupled to zigzag Phosphorene nanoribbon

• Published in: Physics letters. A 2021-01, Vol.387, p.127012, Article 127012
• Main Authors: Amini, Mohsen, Soltani, Morteza, Baninajarian, Samira, Rezaei, Mohsen
• Format: Article
• Language: English
• Subjects: Fano resonance; Two-level quantum system; Vacancy; Zigzag Phosphorene nanoribbon
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2020.127012

•A theoretical description of the physics of interference mechanism for two nearby vacancy defects in a zPNR is presented.•The analytical expression for the wave function associated with two nearby vacancies in phosphorene is introduced.•An interesting realization of a two-level quantum system in the material is proposed.•A new way to tune the electronic transport properties of zPNR in practice is suggested. Double-level quantum systems are good candidates for revealing coherent quantum transport properties. Here, we consider quantum interference effects due to the formation of a two-level system (TLS) coupled to the edge channel of a zigzag Phosphorene nanoribbon (ZPNR). Using the tight-binding approach, we first demonstrate the formation of a TLS in bulk Phosphorene sheet due to the existence of two nearby vacancy impurities. Then, we show that such a TLS can couple to the quasi-one-dimensional continuum of the edge states in a ZPNR which results in the appearance of two-dip Fano-type line shapes. To this end, we generalize the Lippmann–Schwinger approach to study the scattering of edge electrons in a ZPNR by two coupled impurity defects. We obtain an analytical expression of the transmission coefficient which shows that the positions and widths of the antiresonances can be controlled by changing the intervacancy distance as well as their distance from the edge of the ribbon. This work constitutes a clear example of the multiple Fano resonances in mesoscopic transport.