Voltage control of the spin-dependent interaction constants of Dipolaritons and its application to Optical Parametric Oscillator

Abstract

Dipolariton is a voltage controlled mixture of direct and indirect excitons in asymmetric double quantum wells coupled by resonant carrier tunneling, and a microcavity photon. We calculate the voltage dependence of the spin-singlet and spin-triplet interaction parameters $\alpha_{1}$ and $\alpha_{2}$. Both parameters can reach values one order of magnitude larger than that of exciton-polaritons thanks to the strong interaction between indirect excitons. We show that the variation of the indirect exciton fraction of the dipolaritons induces a changes of sign of $\alpha_{2}$ increasing voltage: the interaction passes from attractive to repulsive. For large enough voltage $\alpha_{2}$ becomes larger than $\alpha_{1}$ which in principle can lead to the formation of a circularly polarised dipolariton condensate. We propose an application of the $\alpha_{2}$ dependence to a voltage-controlled dipolaritonic optical parametric oscillator. The change of sign of $\alpha_{2}$ allows an on-site control of the linear polarization degree of the optical signal and its on-demand inversion.