Narrow Results

The effects of the electric field on the coherence time of a 2D RbCl parabolic quantum dot (PQD) qubit are studied by using the variational method of Pekar type (VMPT) and the Fermi Golden Rule. We calculate the excitation energy of an electron strongly coupled to bulk longitudinal optical (LO) phonons in the 2D RbCl PQD under an applied electric field. The phonon spontaneous emission causes the decoherence of the qubit. The investigated results indicate that the coherence time increases with increasing strength of the electric field and the effective confinement length, whereas it decreases with increasing polaron radius. Our research results would be useful for the design and implementation of the solid-state quantum computation.

In this work, the energies and eigenfunctions of ground state and first-excited states (GFES) of a strongly coupled polaron in a quantum pseudo-dot (QPD) were studied by using variational method of Pekar type (VMPT). A single qubit can be realized in this two-level quantum system. Then, we calculated the coherence time of a QPD qubit by employing the Fermi Golden Rule. The temperature effects on the coherence time are taken into account by using the quantum statistics theory (QST) and self-consistent calculation method. According to the obtained results, it is found that the coherence time increases with decreasing temperature. Also, this time is a decaying function of the chemical potential of the two-dimensional electron gas and the zero point of the PHP.