Fluctuations superconducting

THERMAL COLOR-SUPERCONDUCTING FLUCTUATIONS IN DENSE QUARK MATTER... 

Thermal Color-superconducting Fluctuations in DenseQuark Matter... 

As a final example, let us mention that Little 143,144) has discussed the possibility of obtaining organic superconductors that operate at high temperature. The first superconductive model compound to be proposed was a polymethine chain connected with highly polarizable sensitizing cyanine dyes (see e.g. Table 3). The first report on superconducting fluctuations in tetrathiafulvalene-tetra-cyanochinodimethane crystals appeared recently 145>. 2... 

Summary. Various experimental observations of the superconductor-insulator transition are described and compared with two theoretical models one based on boson-vortex duality and the other where the superconducting fluctuations at low temperatures in the magnetic field are calculated. The latter shows that the superconducting fluctuations in dirty but homogeneous superconductor act as grains in a granular superconductor. 

Abstract We will summarize here some of our measurements of the superconducting fluctuations effects on the in-plane electrical resistivity (the so-called in-plane para-conductivity) in La2-i-SrTCu04 thin films with different Sr content. Our results suggest that these superconducting fluctuations effects are not related to the opening of a pseudogap in the normal-state of underdoped compounds. 

The difference between p(T) and pb(T) (dark region in Fig. lb) is supposed to be due to the presence of coherent Cooper pairs created in the normal state by thermal fluctuations. As usual, these superconducting fluctuations (SCF) effects m ay be quantifi ed through the so-called in- plane paraconductivity,... 

For U < 0, the analysis of Emery [16] captures the essence. The attractive interaction favors singlet pairing and the system develops superconducting fluctuations. The charge- or pair-density fluctuations are gapless in the absence of umklapp processes. The spin excitations develop a gap of order U since singlet pairs need to be broken to create spin excitations. 

The only window for superconducting fluctuations in the repulsive sector (Section IV.C.l.a) is below the nonadiabatic crossover ttT°p < under the conditions of small Coulomb interactions and sizable (negative) g2ph... 

The physical origin of this zero-frequency collective mode is not yet clarified. Two possible mechanisms could be considered (1) the onset of superconducting fluctuations below 30 K, and (2) the contribution of sliding... 

From such a field dependence of the pseudospin gap, it is concluded that the pseudogap in the overdoped regime is due to the effects of the fluctuating Cooper pair density above Tc the effect of the strong magnetic field is to quench the superconducting fluctuations.93... 

Mermin-Wagner theorem (5). This theorem forbids long-range order in one and two dimensions at finite temperature, permitting only superconducting fluctuations ("para superconductivity) to survive. With a smalt amount of interplanar hopping, the correlation length in the vertical direction increases from zero to a finite value. But in many other respects, the present mechanism is inherently... 

Superconductivity was first discovered in mercury by H. Kamerlingh Onnes in 1911 (329) and eluded attempts at explanation until, in 1957, Bardeen, Cooper, and Schrieffer formulated the BCS theory (29) based on an electron-lattice-electron interaction. This theory and two others [by W. A. Little (268) and H. Frohlich (152)] are briefly described a full review is beyond the scope of this article. Interest in this area has been heightened by the report of superconducting fluctuations in the one-dimensional organic material, tetrathio-fulvalenium tetracyanoquinodimethanide, (TTF)(TCNQ) (97). 

Theoretically and experimentally the transition from a normal metal to superconductor is preceded (above Tc) by a rapid rise in the conductivity (13, 332), termed paraconductivity or superconducting fluctuations. The temperature dependence of the paraconductivity depends upon the system being one-, two-, or three-dimensional (392). 

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