Effects of temperature and hydrogen-like impurity on the coherence time of RbCl parabolic quantum dot qubit

•We study coherence time of parabolic quantum dot (PQD) qubit.•Hydrogen-like impurity effect on coherence time of qubit.•Temperature effect on coherence time of qubit.•A single qubit can be realized in this two-level quantum system.•The phonon spontaneous emission causes decoherence of the qubit.

By using a variational method of Pekar type, the Fermi Golden Rule and the quantum statistics theory (VMPTFGRQST), we investigate the effects of the hydrogen-like impurity and temperature on the coherence time of a parabolic quantum dot (PQD) qubit with a hydrogen-like impurity at the center. We then derive the ground and the first excited states' (GFES) eigenenergies and the eigenfunctions in a PQD. A single qubit can be realized in this two-level quantum system. The phonon spontaneous emission causes the decoherence of the qubit. The numerical results show that the coherence time is a decreasing function of the temperature, the strength of the Coulombic impurity potential (CIP) and the polaron radius (PR).