Naslov
Mechanism of metallization and superconductivity suppression in YBa2Cu2.97Zn0.03O6.92 revealed by 67Zn NQR

Autori
Pelc, Damjan ; Požek, Miroslav ; Despoja, Vito ; Sunko, Denis

Izvornik
New journal of physics (1367-2630) 17 (2015); 083033, 10

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
high-temperature superconductors ; zinc doping ; NQR ; DFT

Sažetak
We measure the NQR signal on the Zn site in nearly optimally doped YBa2Cu3O6:92, when Cu is substituted by 3% isotopically pure 67Zn. We observe that Zn creates large insulating islands, confirming two earlier conjectures, that doping provokes an orbital transition in the CuO2 plane, which is locally reversed by Zn substitution, and that the islands are antiferromagnetic. Cluster and DFT calculations show that the D4 symmetry breaking, observed directly in the NQR signal here, is due to the same partial lifting of degeneracy of the nearest-neighbor oxygen sites as in the LTT transition in La2-xBaxCuO4, similarly well-known to strongly suppress superconductivity. These results prove that in-plane oxygen 2p5 orbital configurations are principally involved in the metallicity and SC of all high-Tc cuprates, and provide a qualitative symmetry-based constraint on the SC mechanism.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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