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Detection and Implications of a Time-reversal breaking state in underdoped Cuprates
We present general symmetry considerations on how a Time-reversal breaking
state may be detected by angle-resolved photoemission using circularly
polarized photons as has been proposed earlier. Results of recent experiments
utilizing the proposal in underdoped cuprates are analysed and found to be
consistent in their symmetry and magnitude with a theory of the Copper-Oxides.
These togather with evidence for a quantum critical point and marginal
Fermi-liquid properties near optimum doping suggest that a valid microscopic
theory of the phenomena in the cuprates has been found.Comment: A statement on detecting the Anyon state is added and some typos are
subtracte
Dielectric properties of Li2O-3B2O3 glasses
The frequency and temperature dependence of the dielectric constant and the
electrical conductivity of the transparent glasses in the composition
Li2O-3B2O3 (LBO) were investigated in the 100 Hz- 10 MHz frequency range. The
dielectric constant and the loss in the low frequency regime were electrode
material dependent. Dielectric and electrical relaxations were respectively
analyzed using the Cole-Cole and electric modulus formalisms. The dielectric
relaxation mechanism was discussed in the framework of electrode and charge
carrier (hopping of the ions) related polarization using generalized Cole-Cole
expression. The frequency dependent electrical conductivity was rationalized
using Jonscher's power law. The activation energy associated with the dc
conductivity was 0.80 \pm 0.02 eV, which was ascribed to the motion of Li+ ions
in the glass matrix. The activation energy associated with dielectric
relaxation was almost equal to that of the dc conductivity, indicating that the
same species took part in both the processes. Temperature dependent behavior of
the frequency exponent (n) suggested that the correlated barrier hopping model
was the most apposite to rationalize the electrical transport phenomenon in
Li2O-3B2O3 glasses. These glasses on heating at 933 K/10h resulted in the known
non-linear optical phase LiB3O5.Comment: 32 pages, 13 figure
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