One-dimensional superconductor

We first review the two papers [3, 4] where, using semidefinite programming, the 3-matrix of a one-dimensional superconductor was calculated for a... 

There seems to be a growing consensus that the superconductivity is d-wave [97], more specifically, dx2 y2 type. Recent microwave measurements [98] would indicate that the penetration depth is linear in temperature, a sign that the gap has zeros. As pointed out in Ref. 99, this does not exclude 5-wave pairing since harmonics of the basic combinations [Eq. (38)] can also lead to zeros of the gap on the Fermi surface. It is interesting to note that d-wave pairing is quite in line with the extrapolations of the two-dimensional Hubbard and t-J models (Section V.B) and the observed competition with AFM. This would point to a spin-exchange mechanism. The parallel with the quasi-one-dimensional superconductors is striking. 

TMTSF)2C104 [TMTSF is tetramethyltetraselenafulvalene], an ambient-pressure one-dimensional superconductor of the Bechgaard salt family... 

A recent study of the isotope shift in 34S-substituted k phases [92] has ruled out either a dominant role for the C—S stretching motions or a conventional BCS isotope effect involving the ET molecules as the relevant mass entity. There is still the possibility for the pairing in k phases to be related to a non-phonon-mediated mechanism such as the interplane exchange of spin fluctuations as proposed by Bourbonnais and Caron [82] in the context of one-dimensional superconductors. 

By analogy with their previous work3 on a one-dimensional superconductor with many bands, they write down the pair-pair.correlation function as... 

In the 1960s, a completely new form of organic conductors was found. Structurally, these new conductors turned out to be one-dimensional stacks of planar molecules. The conductivity is in the direction perpendicular to the tt-system. In the 1980s, Klaus Bechgaard, and Denis Jerome discovered organic, one-dimensional superconductors. 

Various Ru-oxides, YBa2Cu307, c (I), Ba Ru2/3Gdi/303 (II) as well as Ru-doped a-Fe203 (III), to probe the local chemical structure around the Ru atoms. Compound (I) has interesting properties with x < 0.2 it is a superconductor and with x 1 a semiconductor. Ru oxidation state and coordination are discussed on the basis of measured isomer shifts and quadrupole splittings Ru(IV) ions exclusively occupy Cu-1 sites which form one-dimensional chains... 

See Scanning tunneling spectroscopy Superconductors 332—334 Surface Brillouin zone 92 hexagonal lattice 133 one-dimensional lattice 123, 128 square lattice 129 Surface chemistry 334—338 hydrogen on silicon 336 oxygen on silicon 334 Surface electronic structures 117 Surface energy 96 Surface potential 93 Surface resonance 91 Surface states 91, 98—107 concept 98... 

Attempts have also been made to design one-dimensional organic superconductors based on donor-acceptor interaction (Bechgaard Jerome, 1982). For this purpose it... 

The polymer (SN) is not only metallic but becomes a superconductor at 0.26 K (Hatfield, 1978). Another quasi one-dimensional compound showing superconductiv-... 

Structure of YBa2Cu307. reproduced from G. F. Holland and A. M. Stacy, Physical Properties of the Quaternary Oxide Superconductor YBa2Cu3Ox, Acc. Chem. Res. 1988, 21, 8. One-dimensional Cu-O chains (shown in color) run along the crystallographic t>-axis, and two-dimensional Cu-O sheets lie in the a-b plane. Loss of colored oxygen atoms from the chains at elevated temperature results in YBa2Cu306. 

The range of possibilities for semiconduction is very great, and the applications to the operation of transistors and related devices have revolutionized the electronics industry, but an extensive discussion of these topics is beyond the scope of this text.2 Note, however, that inorganic compounds are receiving intensive attention as the source of semiconductors, superconductors (page 285), and one-dimensional conductors (Chapter 16). 

D. Jerome and L. G. Caron (Eds.), Low Dimensional Conductors and Superconductors, NATO Advanced Study Institute, Series B, Vol. 155, (Plenum, New York 1987) J.T. Devreese (Ed.), Highly Conducting One-Dimensional Solids, (Plenum, New York/London 1979) G. Griiner, Density Waves in Solids (Addison-Wesley, London, 1994)... 

Future developments in this field will surely be dominated by issues relating to the limited dimensionality of the compounds so often found in the organics. As alluded to earlier, such concepts as limited dimensionality and quasi-one-dimensionality were not part of the everyday vocabulary of condensed-matter physics, nor were they part of the world of superconductivity until work focused on problems of organic superconductors. It was this that brought these concepts to the fore, notably through work in the late 1960s of Ferrell [37], Rice [38], and Hohenberg [39] on fluctuations and the innovative microscopic treatment of competition between super-... 

Whenever ta tb the Fermi surfaces will be closed. This is the case with most of the ET salts and the high-temperature superconductors. These solids are intrinsically quasi-two-dimensional. The RG does not apply since there is no one-dimensional regime. Nesting is relevant to only few ET, a... 

There is a fair amount of unity, as seen in Section VI, in the mechanisms of phase transitions of the organic conductors and the oxide superconductors. Correlations, be they inter- or intramolecular, play an important role. Quantum and thermal fluctuations are important in the quasi-one-dimensional solids and, to a lesser extent, in the quasi-two-dimensional conductors. There is a striking richness of phases and unusual phenomena in the organic conductors. These are explored in the following chapters of this book. 

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