Details

Autor(en) / Beteiligte

• Ebrahimnejad, Hadi
• Sawatzky, George A
• Berciu, Mona

Titel

The dynamics of a doped hole in a cuprate is not controlled by spin fluctuations

Ist Teil von

• Nature physics, 2014-12, Vol.10 (12), p.951-955

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Understanding what controls the dynamics of the quasiparticle that results when a hole is doped into an antiferromagnetically ordered CuO2 layer is the rst necessary step in the quest for a theory of the high-temperature superconductivity in cuprates. Here we show that the long-held belief that the quantum spin uctuations of the antiferromagnetic background play a key role in determining this dynamics is wrong. Indeed, we demonstrate that the correct, experimentally observed quasiparticle dispersion is generically obtained for a three-band model describing the hole moving on the oxygen sublattice and coupled to a Nel lattice of spins without spin uctuations. We argue that results from one-band model studies actually support this conclusion, and that this signicant conceptual change in our understanding of this phenomenology opens the way to studying few-hole dynamics, to accurately gauge the strength of the magnetic glue and its contribution to superconductivity. Twenty-seven years after the discovery of high-temperature superconductivity, consensus on its theoretical explanation is still absent. To a good extent, this is due to the difficulty of studying strongly correlated systems near half-filling, needed to understand the behaviour of one or a few holes doped into a CuO2 layer. To simplify this task it is customary to replace three-band models describing the doping holes as entering the O 2p orbitals of these charge-transfer insulators with much simpler one-band Hubbard or tJ models.