TY - JOUR
T1 - Jahn-teller (reverse sign) mechanism for superconductive pairing
AU - Englman, R.
AU - Halperin, B.
AU - Weger, M.
PY - 1990/8/1
Y1 - 1990/8/1
N2 - Band structure calculations and some recent experiments indicate the involvement of both dθ(z2) and dε{lunate}(x2-y2) type states in the carrier states of cuprate superconductors. Electron-phonon coupling, or an excitonic process having similar symmetry properties, leads to a dθ-dε{lunate} pairing mechanism that has the same form as, but a reverse sign to that in the BCS theory so that states that lie close in energy are repelled and those that lie farther apart are attracted. Cooper pairs and gap parameters are derived and are found to be relatively stable against lattice distortion, to be of short range and to exhibit various kinds of isotope effects. The reverse sign model shows stability in situations where dθ and dε{lunate} states are degenerate or are split, the latter provided that the electron-phonon coupling is sufficiently strong so that the superconducting gap energies exceed the splitting.
AB - Band structure calculations and some recent experiments indicate the involvement of both dθ(z2) and dε{lunate}(x2-y2) type states in the carrier states of cuprate superconductors. Electron-phonon coupling, or an excitonic process having similar symmetry properties, leads to a dθ-dε{lunate} pairing mechanism that has the same form as, but a reverse sign to that in the BCS theory so that states that lie close in energy are repelled and those that lie farther apart are attracted. Cooper pairs and gap parameters are derived and are found to be relatively stable against lattice distortion, to be of short range and to exhibit various kinds of isotope effects. The reverse sign model shows stability in situations where dθ and dε{lunate} states are degenerate or are split, the latter provided that the electron-phonon coupling is sufficiently strong so that the superconducting gap energies exceed the splitting.
UR - http://www.scopus.com/inward/record.url?scp=0025470228&partnerID=8YFLogxK
U2 - 10.1016/0921-4534(90)90193-I
DO - 10.1016/0921-4534(90)90193-I
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AN - SCOPUS:0025470228
SN - 0921-4534
VL - 169
SP - 314
EP - 324
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - 3-4
ER -