相关论文: Unconventional pairs glued by conventional phonons…
The common wisdom that the phonon mechanism of electron pairing in the weak-coupling Bardeen-Cooper-Schrieffer (BCS) superconductors leads to conventional s-wave Cooper pairs is revised. An inevitable anisotropy of sound velocity in…
Unconventional superconductivity is commonly linked to electronic pairing mechanisms, since it is believed that the conventional electron-phonon interaction (EPI) cannot cause sign-changing superconducting gap symmetries. Here, we show that…
There is compelling evidence for a strong electron-phonon interaction (EPI) in cuprate superconductors from the isotope effects on the supercarrier mass, high resolution angle resolved photoemission spectroscopies (ARPES), a number of…
Basic experimental facts related to ARPES, tunnelling, optics ad neutron scattering measurements are discussed. They give evidence for the relevance of the electron-phonon interaction (EPI) in pairing mechanism of HTSC cuprates. A…
The important role of the electron-phonon interaction (EPI) in explaining the properties of the normal state and pairing mechanism in high-T$_{c}$ superconductors (HTSC) is discussed. A number of experimental results are analyzed such as:…
In conventional superconductors, phonons glue two electrons with opposite spins to form Cooper pairs and condensation of these pairs leads to the superconductivity. Identifying the underlying mechanism of the high temperature…
Breaking down the traditional perception on phonons which are achiral, the recent discovery of chiral phonon carrying angular momentum provides possible ways to couple electron, photon, spin, magnon and exciton, etc. We theoretically…
Isotope effect with a large coefficient $\alpha=-\partial \ln T_c/\partial \ln M$ is usually taken as an evidence of phonon mediated superconductors in the Bardeen-Cooper-Schrieffer (BCS) theory. However, in cuprates which are now widely…
A possibility of the odd-frequency pairing in the strong-coupling electron-phonon systems is discussed. Using the Holstein-Hubbard model, we demonstrate that the anomalously soft Einstein mode with the frequency $\omega_{\rm…
Superconductivity in high-Tc cuprates is unconventional and there is a growing acceptance that carrier pairing in these strongly correlated electronic materials is mediated mainly by bosons of electronic origin rather than the phonons.…
Developing a theory of high-temperature superconductivity in copper oxides is one of the outstanding problems in physics. It is a challenge that has defeated theoretical physicists for more than twenty years. Attempts to understand this…
Understanding exotic, non s--wave--like states of Cooper pairs is important and may lead to new superconductors with higher critical temperatures and novel properties. Their existence is known to be possible but has always been thought to…
We investigate a model for the CuO_2 plane of high-T_c superconductors where the charge carriers are coupled to A_{1g} and B_{1g} symmetric out-of plane vibrations of the oxygen atoms in the presence of local Hubbard correlations. The…
Confirmation of the phononic origin of Cooper pair formation in superconductors came with the demonstration that the interaction was retarded and that the corresponding energy scales were associated with phonons. Using cellular dynamical…
The successful application of the electron-phonon interaction (EPI) mechanism in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity is among the most outstanding intellectual achievements in theoretical physics…
In this thesis, we theoretically examine the pairing mechanisms and the identification of the pairing symmetry of unconventional superconductors whose normal states are correlated, multiband, or topological. In the first part, we…
Conventional superconductivity, as used in this review, refers to electron-phonon coupled superconducting electron-pairs described by BCS theory. Unconventional superconductivity refers to superconductors where the Cooper pairs are not…
Using high resolution angle-resolved photoemission data in conjunction with that from neutron and other probes, we show that electron-phonon (el-ph) coupling is strong in cuprates superconductors and it plays an important role in pairing.…
The polaron binding energy E_{p} in undoped parent cuprates has been determined to be about 1.0 eV from the unconventional oxygen-isotope effect on the antiferromagnetic ordering temperature. The deduced value of E_{p} is in quantitative…
In conventional superconductors, the electron-phonon coupling plays a dominant role in pairing the electrons and generating superconductivity. In high temperature cuprate superconductors, the existence of the electron coupling with phonons…