Mass-profile quantum dots in graphene and artificial periodic structures

Article

关键词: TOPOLOGICAL INSULATORS;    MAGNETIC-FIELDS;    SYMMETRY;   

DOI  :  10.1103/PhysRevB.91.165415

来源: SCIE

【 摘 要 】

We analyze the bound-state spectra of mass-profile quantum dots in graphene, a system at current experimental reach. Homogeneous perpendicular magnetic fields are also considered which result in breaking the valley degeneracy. The spectra show rich features, arising from the chiral band structure of graphene and its Landau levels and we identify three different regimes depending on the ratio between the radius of the dot and the magnetic length. We further carry out a comparison with potential-well quantum dots discussed in Recher et al. [Phys. Rev. B 79, 085407 (2009)] and conclude that mass confinement may offer significant advantages for optical applications in the THz and infrared regime. Also due to experimental advances, we additionally analyze the band structure of a linear chain of mass-profile quantum dots, where overlap-assisted hopping processes play a major role for closely packed arrays. The inclusion of Coulomb interactions between electron-hole pairs of adjacent sites leads to a new regime where Forster transfer processes become dominant.

【 授权许可】

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