TY - JOUR

T1 - AC conductivity and the anomalous dielectric constant of a disordered two-dimensional system

AU - Ben-Zimra, Donita

AU - Kaveh, Moshe

PY - 1987/1/10

Y1 - 1987/1/10

N2 - The authors calculate the AC conductivity for a disordered two-dimensional system and find a transition between diffusive-like behaviour and hopping-like behaviour. In the diffusive region, (r2) approximately tw with w<1 and sigma diff approximately omega 1-w. This behaviour is found to be consistent with power-law localisation with w=1/(1+s) where s is the exponent of the power-law wavefunction, mod psi mod approximately r-s. In the hopping region, the authors find sigma hop approximately omega 2-3s/. This leads to an anomalous dielectric constant epsilon 1 which diverges at two values of energy, at the mobility edge and at an energy for which s=3. For s>3, epsilon 1 is finite and positive down to the mobility edge Ec. Below Ec, the dielectric constant diverges as epsilon 1 approximately (Ec-E)-(4 nu -1) where nu is the exponent of the localisation length xi approximately (Ec-=E)- nu.

AB - The authors calculate the AC conductivity for a disordered two-dimensional system and find a transition between diffusive-like behaviour and hopping-like behaviour. In the diffusive region, (r2) approximately tw with w<1 and sigma diff approximately omega 1-w. This behaviour is found to be consistent with power-law localisation with w=1/(1+s) where s is the exponent of the power-law wavefunction, mod psi mod approximately r-s. In the hopping region, the authors find sigma hop approximately omega 2-3s/. This leads to an anomalous dielectric constant epsilon 1 which diverges at two values of energy, at the mobility edge and at an energy for which s=3. For s>3, epsilon 1 is finite and positive down to the mobility edge Ec. Below Ec, the dielectric constant diverges as epsilon 1 approximately (Ec-E)-(4 nu -1) where nu is the exponent of the localisation length xi approximately (Ec-=E)- nu.

UR - http://www.scopus.com/inward/record.url?scp=84870488206&partnerID=8YFLogxK

U2 - 10.1088/0022-3719/20/1/012

DO - 10.1088/0022-3719/20/1/012

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AN - SCOPUS:84870488206

SN - 0953-8984

VL - 20

SP - 83

EP - 89

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

IS - 1

ER -