无序度对一维长程关联无序系统中局域化-退局域化转变的影响

对长程幂律关联能量序列进行了修正，使其能体现出无序度在一维长程关联无序系统中的影响，并利用重正化群方法，计算了能反映该系统局域化-退局域化转变的Lyapunov指数.结果表明，在由于关联指数p的影响而在系统中出现的局域化向退局域化的转变中，无序度起着相反的作用.当关联指数p一定而无序度W增大时，系统中心能区范围内由于长程关联而引起的扩展态逐渐向局域态转变.当无序度W增大到某一临界值W_c时，系统中所有本征态均转变为局 关键词： 长程关联 Lyapunov指数 无序度 局域化-退局域化转变

Effect of disorder degree on the localization-delocalization transition in one-dimensional disordered system with long-range correlations

In order to reveal the effect of disorder degree on the localization-delocalization transition in one-dimensional disordered system with long-range correlations, the long-range power-law correlated energy sequence was modified. By using the renormalization group method, the Lyapunov exponent characterizing the localization-delocalization transition was calculated. The results showed that, compared with the correlation exponent, the disorder degree plays an opposite role in this transition. When the correlation exponent was fixed but the disorder degree increased, the extended states, which appeared at the center of energy band due to the influence of long-range correlations, were gradually converted to localized states. When the disorder degree increased to a critical value W_c, the whole eigenstates of the system became localized states, and the critical value W_c increased with the increase of correlation exponent.