Eur. Phys. J. Plus (2016) 131: 75
https://doi.org/10.1140/epjp/i2016-16075-9

Regular Article

Temperature, impurity and electromagnetic field effects on the transition of a two-level system in a triangular potential

¹ Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
² Laboratory of Electronics and Signal Processing, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon
³ Laboratory of Mechanics and Modeling of Physical Systems, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon

^* e-mail: fotuea@yahoo.fr

Received: 1 December 2015
Accepted: 5 February 2016
Published online: 4 April 2016

Abstract

Using the Pekar variational method, the effects of the temperature, impurity and electromagnetic fields on the transition are investigated through the eigenenergies of the ground and first-excited states of the polaron in a triangular potential quantum dot. Those parameters are essential for the transition of the polaron from the ground state to the first-excited state. This quantum system in nanostructure can be employed as a two-level quantum qubit. The numerical result shows the weak evolution of the probability density with the electron-phonon coupling constant, the cyclotron frequency and the Coulombic potential. It is also noted that this probability increased with the confinement length and electric-field strength. The tunneling of temperature leads to the amplification of the probability density.