Persistent electrical doping of Bi2Sr2CaCu2O8+x mesa structures
2012 (English)In: Physical Review B, ISSN 2469-9950, Vol. 85, no 14, 144519Article in journal (Refereed) Published
Application of a significantly large bias voltage to small Bi2Sr2CaCu2O8+x mesa structures leads to persistent doping of the mesas. Here, we employ this effect for analysis of the doping dependence of the electronic spectra of Bi-2212 single crystals by means of intrinsic tunneling spectroscopy. We are able to controllably and reversibly change the doping state of the same single crystal from underdoped to overdoped state, without changing its chemical composition. It is observed that such physical doping is affecting superconductivity in Bi-2212 similar to chemical doping by oxygen impurities: with overdoping, the critical temperature and the superconducting gap decrease; with underdoping, the c-axis critical current rapidly decreases due to progressively more incoherent interlayer tunneling and the pseudogap rapidly increases, indicative for the presence of the critical doping point. We distinguish two main mechanisms of persistent electric doping: (i) even-in-voltage contribution, attributed to a charge transfer effect, and (ii) odd-in-voltage contribution, attributed to reordering of oxygen vacancies.
Place, publisher, year, edition, pages
2012. Vol. 85, no 14, 144519
Condensed Matter Physics
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-80276DOI: 10.1103/PhysRevB.85.144519ISI: 000302958900003OAI: oai:DiVA.org:su-80276DiVA: diva2:557144