Metastable electron-electron states in double-layer graphene structures
Physical Review B - Condensed Matter and Materials Physics
American Physical Society
©2015 American Physical Society. This is the final version of the article. Available from American Physical Society via the DOI in this record.
The prototypical exciton model of two interacting Dirac particles in graphene was analyzed in J. Sabio, Phys. Rev. B 81, 045428 (2010)PRBMDO1098-012110.1103/PhysRevB.81.045428 and it was found that in one of the electron-hole scattering channels the total kinetic energy vanishes, resulting in a singular behavior. We show that this singularity can be removed by extending the quasiparticle dispersion, thus breaking the symmetry between upper and lower Dirac cones. The dynamics of an electron-electron pair are then mapped onto that of a single particle with negative mass and anisotropic dispersion. We show that the interplay between dispersion and repulsive interaction can result in the formation of bound, Cooper-pair-like, metastable states in double-layered hybrid structures.
The authors wish to thank V. I. Fal’ko and M. V. Berry for insightful discussions. A.V.S. is supported by EPSRC/HEFCE Grant No. EP/G036101/1.
Vol. 92, Issue 8, Article no. 085409