Scaling Properties of Energy Gap in Dimerized Spinless Fermion Chains with Quasiperiodic Modulation
Li Peng-Fei; Chen Yu-Guang; Chen Hong; Li Peng-Fei; Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092; Chen Yu-Guang; Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092; Chen Hong; Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092
Журнал:
Chinese Physics Letters
Дата:
2007-04-01
Аннотация:
By employing the exact diagonalization method, we investigate the low-energy behaviour of the dimerized spinless fermion chains with quasiperiodic modulation. It is found that for off-diagonal modulation, the energy gap with length N scales as exp(−cN<sup>ω</sup>) with nonuniversal exponent ω if the dimerization is nonzero. However, for diagonal modulation, there may exist a critical dimerization δ<sub>c</sub> beyond which the system exhibits a metal–insulator transition.
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