Modulations of superradiance and quantum entanglement of quantum emitters in terahertz frequency

We study the superradiance and entanglement phenomena between two quantum emitters (QEs) operating at terahertz (THz) frequencies, facilitated by the presence of a topological insulator bismuth selenide (Bi2Se3). Controlled by the hyperbolic phonon polaritons and electron surface state in the terahertz (THz) frequency range, the interaction between QEs is significantly enhanced both within and outside the hyperbolic bands. Moreover, the entanglement between two QEs through Bi2Se3 is studied in detail. Certain initial entanglement states undergo sudden death of entanglement when the system is in non-interaction. However, in the cases of moderate or strong interaction, the entanglement can be revive after experiencing the sudden death phenomenon. These findings hold significant implications for controlling the interaction of QEs and their potential applications in the fields of quantum metrology and quantum imaging in the THz frequency region.