The Effects of Temperature and Electric Field on a Quantum Rod Qubit

Abstract

The Hamiltonian of a quantum rod (QR) with an ellipsoidal boundary is given after a coordinate transformation, which changes the ellipsoidal boundary into a spherical one. We then study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron strongly coupled to LO-phonon under an applied electric field by using variational method of Pekar type. This QR system may be used as a two-level quantum qubit. When the electron is in the superposition state of the ground and the first excited states, we obtained the time evolution of the electron probability density oscillating in the QR with a certain period. We then investigate the effects of the temperature and the electric field on the time evolution of the electron probability density and the oscillation period. It is found that the electron probability density and the oscillation period increase (decrease) with increasing temperature in lower (higher) temperature regime. The electron probability density decreases (increases) with increasing electric field when the temperature is lower (higher). The oscillation period decreases with the increase of the electric field along the ρ x direction.