Exciton-polarons in doped semiconductors in a strong magnetic field

Article

关键词: NEGATIVELY CHARGED EXCITONS;    2-DIMENSIONAL ELECTRON-GAS;    QUANTUM-WELLS;    EXCITATIONS;    TRIONS;    STATES;    ABSORPTION;   

DOI  :  10.1103/PhysRevB.97.235432

来源: SCIE

【 摘 要 】

In previous work, we have argued that the optical properties of moderately doped two-dimensional semiconductors can be described in terms of excitons dressed by their interactions with a degenerate Fermi sea of additional charge carriers. These interactions split the bare exciton into attractive and repulsive exciton-polaron branches. The collective excitations of the coupled system are many-body generalizations of the bound trion and unbound states of a single electron interacting with an exciton. In this paper, we consider exciton-polarons in the presence of an external magnetic field that quantizes the kinetic energy of the electrons in the Fermi sea. Our theoretical approach is based on a transformation to a new basis that respects the underlaying symmetry of magnetic translations. We find that the attractive exciton-polaron branch is only weakly influenced by the magnetic field, whereas the repulsive branch exhibits magnetic oscillations and splits into discrete peaks that reflect combined exciton-cyclotron resonance.

【 授权许可】

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