Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Conference Object Citation - WoS: 7Citation - Scopus: 7Aspects of the Tunneling Dip Feature in Bi2sr2cacu2o8+? and Its Relation To the Resonance Spin Excitation(Elsevier Ltd., 2002) Zasadzinski, John F.; Özyüzer, Lütfi; Miyakawa, Nobuaki; Gray, Kenneth E.; Hinks, David G.; Kendziora, Christopher A.Break-junction tunneling data are reported in Bi2Sr2CaCu2O8+δ over a wide range of hole concentration from underdoped to overdoped. The strong conductance peaks in the superconducting state reveal a single gap consistent with d-wave symmetry. In addition, sharp dips are observed at a voltage, Ω/□, measured with respect to the gap edge. These features are shown to be reproduced in other junction types from the literature including atomically resolved STM and □-axis mesas, establishing their intrinsic character. Trends are observed with doping and temperature which link the dip to the resonance spin excitation and indicate that the quasiparticles are strongly coupled to this mode.Article Citation - WoS: 200Citation - Scopus: 212Predominantly Superconducting Origin of Large Energy Gaps in Underdoped Bi2sr2cacu2o8+? From Tunneling Spectroscopy(American Physical Society, 1999) Miyakawa, Nobuaki; Zasadzinski, John F.; Özyüzer, Lütfi; Guptasarma, Prasenjit; Hinks, David G.; Kendziora, Christopher A.; Gray, Kenneth E.New tunneling data are reported in Bi2Sr2CaCu2O8+δ which show quasiparticle excitation gaps, Δ, reaching values as high as 60 meV for underdoped crystals with Tc = 70 K. These energy gaps are nearly 3 times larger than those of overdoped crystals with similar Tc. Despite the large differences in gap magnitude, the tunneling spectra display qualitatively similar characteristics over the entire doping range. Detailed examination of the spectra, including the Josephson IcRn product measured in break junctions, indicates that these energy gaps are predominantly of superconducting origin.