Progress and perspectives on electron-doped cuprates

Abstract

Although the vast majority of high-Tc cuprate superconductors are hole-doped, a small family of electron-doped compounds exists. Under investigated until recently, there has been tremendous recent progress in their characterization. A consistent view is being reached on a number of formerly contentious issues, such as their order parameter symmetry, phase diagram, and normal state electronic structure. Many other aspects have been revealed exhibiting both their similarities and differences with the hole-doped compounds. This review summarizes the current experimental status of these materials. We attempt to synthesize this information into a consistent view on a number of topics important to both this material class as well as the overall cuprate phenomenology including the phase diagram, the superconducting order parameter symmetry, electron-phonon coupling, phase separation, the nature of the normal state, the role of competing orders, the spin-density wave mean-field description of the normal state, and pseudogap effects.

DMFT Study on the Electron–hole Asymmetry of the Electron Correlation Strength in the High Tc Cuprates

“…Some of these studies suggest that superconductivity persists even with no electron doping, [1][2][3] while others show presence of antiferromagnetic long range order in the lightly doped regime, 4,5) so that the issue is still controversial. It was also shown experimentally that the "pseudo gap", [6][7][8][9][10] a prominent feature of the cuprates, disappears if the antiferromagnetism is suppressed. 11) This is consistent with a theoretical study, which shows that the pseudo gap in the electron-doped case originates from the antiferromagnetism.…”

Spin and charge excitations in artificial hole- and electron-doped infinite layer cuprate superconductors

“…A striking characteristic of the class of cuprate HTS is the marked asymmetry between the phase diagram of h and e-doped compounds: some important physical proprieties, such as pseudogap, charge order and maximum T c , dramatically change from the h-doped to the e-doped side 17,18 . Experiments show that also the paramagnon excitations have a different doping evolution upon hole and electron doping: for h-doped compounds the dispersion is almost unaffected by doping, while for e-doped ones the dispersion is doping dependent, with hardening of the paramagnon mode up to 50% 11,12 .…”

“…SLCO is an e-doped cuprate with different structure than NCCO and other T ′ e-doped compounds 17,18 .…”

Superconductivity from repulsive interaction

“…The KL consideration can also be applied to electron-doped cuprates [113], but the analysis in this case is somewhat different as hot spots are located close to Brillouin zone diagonals [99].…”