The Experts below are selected from a list of 3588 Experts worldwide ranked by ideXlab platform
Sujit Sarkar - One of the best experts on this subject based on the ideXlab platform.
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Isotope-Shift Exponent and the Gap Ratio for d-Wave Pairing within the Phonon Mediated Mechanism
International Journal of Modern Physics B, 1998Co-Authors: Sujit SarkarAbstract:An exact analytical expression for the isotope-shift exponent is derived for the d-wave pairing assuming a phonon-mediated interaction. The role of the orthorhombic distortion and second nearest-neighbor hopping on the transition temperature (Tc) and the isotope-shift exponent (α) are studied. The temperature dependence of the Gap parameter and the doping dependence of the Gap Ratio are also investigated. It is found that introduction of second nearest-neighbor hopping increases Tc) as well as the Gap Ratio while decreases the minimum value of α. The variation of α with doping is qualitatively consistent with the experimental results of high-Tc oxide systems.
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Isotope-shift exponent and the Gap Ratio within the extended saddle point singularity scenario for different pairing symmetries
Physica C-superconductivity and Its Applications, 1997Co-Authors: Sujit SarkarAbstract:Abstract Exact analytical expressions for the isotope-shift exponent are derived within the BCS formalism for different pairing symmetries (isotropic s -wave, extended s -wave, d -wave) and extended saddle point singularity in the density of states (DOS) is considered. The isotope-shift exponent and the Gap Ratio are studied as a function of doping for different symmetries. It is found that the predictions for the d -wave pairing symmetry are closer to the experimental situation in cuprates.
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The superconducting Gap Ratio, isotope-shift exponent and pressure coefficient of Tc for high-Tc systems
Physica B: Condensed Matter, 1996Co-Authors: A. N. Das, Sujit SarkarAbstract:The superconducting Gap Ratio, isotope-shift exponent and the pressure co-efficient of the superconducting transition temperature are studied within different models proposed for high-Tc cuprate oxide systems. A comparison with the experimental results of high-Tc oxide systems is made.
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isotope shift exponent pressure coefficient of tc and the superconducting Gap Ratio within the van hove scenario
Physical Review B, 1994Co-Authors: Sujit SarkarAbstract:Exact expression for the isotope-shift exponent and the pressure coefficient of the transition temperature are derived from the BCS Gap equation for a density of states (DOS) with a van Hove singularity (VHS). The variations of these quantities with the shift of the Fermi level from the VHS and with [ital T][sub [ital c]] are discussed. The superconducting Gap-to-[ital T][sub [ital c]] Ratio (2[Delta][sub 0]/[ital T][sub [ital c]]) is also studied. The value of 2[Delta][sub 0]/[ital T][sub [ital c]] lies in the range from 3.53 to 4 for the DOS with a VHS at the Fermi level. A comparison of theoretical predictions with experimental results of high-[ital T][sub [ital c]] oxide systems are made. A qualitative good agreement is obtained for the pressure coefficient of [ital T][sub [ital c]].
M Bruns - One of the best experts on this subject based on the ideXlab platform.
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penetRation depth microwave surface resistance and Gap Ratio in nbn and ba1 xkxbio3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
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PenetRation depth, microwave surface resistance, and Gap Ratio in NbN and Ba1−xKxBiO3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
M S Pambianchi - One of the best experts on this subject based on the ideXlab platform.
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penetRation depth microwave surface resistance and Gap Ratio in nbn and ba1 xkxbio3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
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PenetRation depth, microwave surface resistance, and Gap Ratio in NbN and Ba1−xKxBiO3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
E H Hartford - One of the best experts on this subject based on the ideXlab platform.
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penetRation depth microwave surface resistance and Gap Ratio in nbn and ba1 xkxbio3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
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PenetRation depth, microwave surface resistance, and Gap Ratio in NbN and Ba1−xKxBiO3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
S M Anlage - One of the best experts on this subject based on the ideXlab platform.
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penetRation depth microwave surface resistance and Gap Ratio in nbn and ba1 xkxbio3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
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PenetRation depth, microwave surface resistance, and Gap Ratio in NbN and Ba1−xKxBiO3 thin films
Applied Physics Letters, 1994Co-Authors: M S Pambianchi, S M Anlage, E S Hellman, E H Hartford, M BrunsAbstract:We report values of the zero temperature magnetic penetRation depth λ(0), microwave surface resistance Rs, and Gap Ratio 2Δ(0)/kBTc in technologically useful thin films of NbN and Ba1−xKxBiO3. A novel analysis technique was used to extract the absolute magnitude of λ(0) and 2Δ(0)/kBTc from shifts in resonant frequency of a parallel‐plate resonator. For NbN and Ba1−xKxBiO3 values of λ(0)=3900±200 A and 3300±200 A were obtained, respectively. The Gap Ratios were found to be 2Δ(0)/kBTc=4.1±0.1 and 3.8±0.5, respectively, for Tc=16.3 K in NbN and Tc=17.2 K in Ba1−xKxBiO3. The surface resistance measurements on Ba1−xKxBiO3 represent the lowest values ever reported at microwave frequencies in this material.
