In this paper, we quantitatively study the quantum diffusion in a bilateral doped chain, which is randomly doped on both sides. A tight binding approximation and quantum dynamics are used to calculate the three electr...In this paper, we quantitatively study the quantum diffusion in a bilateral doped chain, which is randomly doped on both sides. A tight binding approximation and quantum dynamics are used to calculate the three electronic characteristics： autocorrelation function C（t）, the mean square displacement d（t） and the participation number P（E） in different doping situations. The results show that the quantum diffusion is more sensitive to the small ratio of doping than to the big one, there exists a critical doping ratio qo, and C（t）, d（t） and P（E） have different variation trends on different sides of qo. For the self-doped chain, the doped atoms have tremendous influence on the central states of P（E）, which causes the electronic states distributed in other energy bands to aggregate to the central band （E = 0） and form quasi-mobility edges there. All of the doped systems experience an incomplete transition of metal-semiconductor-metal.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10974166 and 10774127)the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China (Grant No.708068)the Research Foundation of Education Bureau of Hunan Province of China (Grant No.09A094)
文摘In this paper, we quantitatively study the quantum diffusion in a bilateral doped chain, which is randomly doped on both sides. A tight binding approximation and quantum dynamics are used to calculate the three electronic characteristics： autocorrelation function C（t）, the mean square displacement d（t） and the participation number P（E） in different doping situations. The results show that the quantum diffusion is more sensitive to the small ratio of doping than to the big one, there exists a critical doping ratio qo, and C（t）, d（t） and P（E） have different variation trends on different sides of qo. For the self-doped chain, the doped atoms have tremendous influence on the central states of P（E）, which causes the electronic states distributed in other energy bands to aggregate to the central band （E = 0） and form quasi-mobility edges there. All of the doped systems experience an incomplete transition of metal-semiconductor-metal.
