Polariton bunching and anti-bunching in a photonic dot controlled by a magnetic field

Using the Liouville-von Neumann equation, we study the polarization dynamics of the polaritons localized in a photonic dot excited by continuous-wave (cw) or pulse laser beams. Pumped by the cw and circularly polarized laser, in the weak magnetic-field region we find a strong polariton anti-bunching and a platform behavior in the variation in the polariton occupation with the pump field, and the latter manifestly displays the polariton quantum blockade. In the case of using the cw and linearly polarized laser, we find the redshift of the polariton energy in the polariton magnetic spectrums, due to the effective-attractive interaction between the polaritons with antiparallel spins; moreover the polaritons with antiparallel spins are always anti-bunching in the low excitation regime. Especially, we demonstrate the single-photon character of the photonic dot in the excitation of the pulsed wave and linearly polarized laser, and the emitted-photon polarization can be conveniently adjusted by an applied magnetic field.