Influences of the impurity and magnetic field on the probability density and the period of the asymmetric Gaussian potential qubit
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The eigenenergies and eigenfunctions of the ground and first-excited states of an electron, which is coupled to an LO-phonon in a quantum dot with an asymmetric Gaussian (AG) potential, Coulomb bound potential and the magnetic field was studied by using Lee-Low-Pines transformation and Pekar variation method. A single qubit can be realized in this two-level quantum system. Numerical results show that the probability density of electrons in the qubit oscillates with changing the time, the well width and the well depth the AG potential. The probability density obviously fluctuates with changes in the magnetic-field cyclotron (MFC) frequency, the dielectric constant (DC) ratio and the electron–phonon coupling (EPC) strength, respectively, which is not conducive to constructing a suitable qubit. The oscillation period of the qubit decreases with increasing the DC ratio, EPC strength and the MFC frequency, respectively, which has an adverse effect on the survival time of qubit.
KeywordsQubit Asymmetric Gaussian potential Probability density Oscillation period Magnetic field Hydrogen-like impurity
This project was supported by the National Natural Science Foundation of China (Grant No. 51902085), the Nature Science Foundation of Hebei Province, China (Grant Nos. E2013407119 and E2019407123) and the Natural Science Foundation of Inner Mongolia Autonomous Region (Grant No. 2019MS01011).
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