Properties of strong-coupling magneto-bipolaron qubit in quantum dot under magnetic field

Abstract

Based on the variational method of Pekar type, we study the energies and the wave-functions of the ground and the first-excited states of magneto-bipolaron, which is strongly coupled to the LO phonon in a parabolic potential quantum dot under an applied magnetic field, thus built up a quantum dot magneto-bipolaron qubit. The results show that the oscillation period of the probability density of the two electrons in the qubit decreases with increasing electron-phonon coupling strength α, resonant frequency of the magnetic field ω c , confinement strength of the quantum dot ω 0 , and dielectric constant ratio of the medium η; the probability density of the two electrons in the qubit oscillates periodically with increasing time t, angular coordinate ϕ 2 , and dielectric constant ratio of the medium η; the probability of electron appearing near the center of the quantum dot is larger, and the probability of electron appearing away from the center of the quantum dot is much smaller.

Probability density of bipolaron in a parabolic potential two-dimensional quantum dot under external magnetic and electric fields

“…In order to increase the lifespan of the qubit it is necessary to choose materials that have low EPC ( ) a for the manufacture of QDs. result in agreement with the following study [21,22].…”

“…In summary, whether we are in the presence of a magnetic field or electronic field the probability of electron appearing near the center of the quantum dot is larger, while that appearing away from the center of the quantum dot is much smaller. These results are in agreement with the results of Zhang ying [21] and Xu-Fang Bai [22]. It is interesting now to show the cumulative effect of electric and magnetic fields on the electron probability density then compare with previous studies.…”

“…They have shown that the external electric field and the dielectric constant ratio both can decrease the coherence of bipolaron qubit. In the same logic, Bai Xu-Fang et al [22] have studied the properties of a strong-coupling magneto-bipolaron qubit in a quantum dot under magnetic field. They have also shown that the external magnetic field and the dielectric constant ratio both can decrease the coherence of bipolaron qubit.…”