摘要
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Wc时,系统中所有本征态均转变为局域态,此时系统中发生退局域化向局域化的转变,并且临界值Wc随着关联指数p的增大而增大.
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 Wc, the whole eigenstates of the system became localized states, and the critical value Wc increased with the increase of correlation exponent.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第4期2415-2420,共6页
Acta Physica Sinica
