WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 3Citation - Scopus: 3Compact Multilayer Thin-Film Color Filters and Direct Integration on White-Light Diodes for Color Conversion(Optical Society of America, 2021) Yiğen, Serap; Ekmekçioğlu, Merve; Özdemir, Mehtap; Aygün, Gülnur; Özyüzer, LütfiWe present highly efficient green, yellow, and red filters based on a metal-dielectric structure. The filters encompass only five layers of alternating zinc tin oxide and silver thin films that are grown on soda lime glass and white light-emitting diodes (LEDs) using direct current magnetron sputtering at room temperature. The designed filters provide efficient color filtering in the visible spectrum. High purity colored light is obtained by direct application of filters on LEDs as color converters. The presented method offers an easy way for realizing different colors by tuning the thicknesses of layers in the structure. (C) 2021 Optical Society of AmericaArticle Citation - WoS: 150Citation - Scopus: 7Correlation of Tunneling Spectra in Bi2sr2cacu2o8+? With the Resonance Spin Excitation(American Physical Society, 2001) Zasadzinski, John F.; Özyüzer, Lütfi; Miyakawa, Nobuaki; Gray, Kenneth E.; Hinks, David G.; Kendziora, Christopher A.New break-junction tunneling data are reported in Bi2Sr2CaCu2O8+δ over a wide range of hole concentration from underdoped (Tc=74k) to optimal doped (Tc=95k) to overdoped (Tc=48k). The conductances exhibit sharp dips at a voltage, Ω/e, measured with respect to the superconducting gap. Clear trends are found such that the dip strength is maximum at optimal doping and that Ω scales as 4.9kTc over the entire doping range. These features link the dip to the resonance spin excitation and suggest quasiparticle interactions with this mode are important for superconductivity.Article Citation - WoS: 28Citation - Scopus: 29Eliashberg Analysis of Tunneling Experiments: Support for the Pairing Glue Hypothesis in Cuprate Superconductors(American Physical Society, 2011) Ahmadi, O.; Coffey, L.; Zasadzinski, John F.; Miyakawa, Nobuaki; Özyüzer, LütfiEvidence for the validity of the pairing glue interpretation of high temperature superconductivity is presented using a modified Eliashberg analysis of experimental superconductor-insulator-superconductor (SIS) tunneling data in B2Sr2CaCu2O8 (Bi2212) over a wide range of doping. This is accomplished by extracting detailed information on the diagonal and anomalous contributions to the quasiparticle self-energy. In particular, a comparison of the imaginary part of the anomalous self-energy ImΦ(ω) and the pairing glue spectral function α2F(ω) used in the model is consistent with Hubbard model simulations in the literature. In addition, the real part of the diagonal self-energy for optimal doped Bi2212 bears a strong resemblance to that obtained from photoemission experiments.Article Citation - WoS: 54Citation - Scopus: 55Persistence of Strong Electron Coupling To a Narrow Boson Spectrum in Overdoped Bi2sr2cacu2o8+î Tunneling Data(American Physical Society, 2006) Zasadzinski, John F.; Özyüzer, Lütfi; Coffey, L.; Gray, Kenneth E.; Hinks, David G.; Kendziora, Christopher A.A d-wave, Eliashberg analysis of break-junction and STM tunneling spectra on Bi2Sr2CaCu2O8+Î (Bi2212) reveals that the spectral dip feature is directly linked to strong electronic coupling to a narrow boson spectrum, evidenced by a large peak in I'2F(I). The tunneling dip feature remains robust in the overdoped regime of Bi2212 with bulk Tc values of 56Â Ka62Â K. This is contrary to recent optical conductivity measurements of the self-energy that suggest the narrow boson spectrum disappears in overdoped Bi2212 and therefore cannot be essential for the pairing mechanism. The discrepancy is resolved by considering the way each technique probes the electron self-energy, in particular, the unique sensitivity of tunneling to the off-diagonal or pairing part of the self-energy.Article Citation - WoS: 660Citation - Scopus: 692Emission of Coherent Thz Radiation From Superconductors(American Association for the Advancement of Science, 2007) Özyüzer, Lütfi; Koshelev, A. E.; Kurter, Cihan; Gopalsami, N.; Li, Q.; Tachiki, M.; Kadowaki, K.; Yamamoto, T.; Minami, H.; Yamaguchi, H.; Tachiki, T.; Gray, Kenneth E.; Kwok, W. K.; Welp, U.Compact solid-state sources of terahertz (THz) radiation are being sought for sensing, imaging, and spectroscopy applications across the physical and biological sciences. We demonstrate that coherent continuous-wave THz radiation of sizable power can be extracted from intrinsic Josephson junctions in the layered high-temperature superconductor Bi2Sr2CaCu 2O8. In analogy to a laser cavity, the excitation of an electromagnetic cavity resonance inside the sample generates a macroscopic coherent state in which a large number of junctions are synchronized to oscillate in phase. The emission power is found to increase as the square of the number of junctions reaching values of 0.5 microwatt at frequencies up to 0.85 THz, and persists up to ∼50 kelvin. These results should stimulate the development of superconducting compact sources of THz radiation.