The properties of an asymmetric Gaussian potential quantum well qubit in RbCl crystal**Project supported by the National Natural Science Foundation of China (No. 11464033) and the Mongolia University for Nationalities Fund (No.NMDYB1445).

Abstract

With the circumstance of the electron strongly coupled to LO-phonon and using the variational method of Pekar type (VMPT), we study the eigenenergies and the eigenfunctions (EE) of the ground and the first excited states (GFES) in a RbCl crystal asymmetric Gaussian potential quantum well (AGPQW). It concludes: (i) Two-energy-level of the AGPQW may be seen as a qubit. (ii) When the electron located in the superposition state of the two-energy-level system, the time evolution and the coordinate changes of the electron probability density oscillated periodically in the AGPQW with every certain period fs. (iii) Due to the confinement that is a two dimensional x−y plane symmetric structure in the AGPQW and the asymmetrical Gaussian potential (AGP) in the AGPQW growth direction, the electron probability density presents only one peak configuration located in the coordinate of z > 0, whereas it is zero in the range of z < 0. (iv) The oscillatory period is a decreasing function of the AGPQW height and the polaron radius. (v) The oscillating period is a decreasing one in the confinement potential R < 0.24 nm, whereas it is an increasing one in the confinement potential R > 0.24 nm and it takes a minimum value in R = 0.24 nm.