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 - 0022-3719
VL - 20
SP - 83
EP - 89
JO - Journal of Physics C: Solid State Physics
JF - Journal of Physics C: Solid State Physics
IS - 1
ER -