We have analytically derived the relaxation function for one-dimensional disordered complex systems in terms of autocorrelation function of fractal time random walk by using operator formalism. We have shown that the ...We have analytically derived the relaxation function for one-dimensional disordered complex systems in terms of autocorrelation function of fractal time random walk by using operator formalism. We have shown that the relaxation function has stretched exponential, i.e. the Kohlrausch-Williams-Watts character for a fractal time random walk process.展开更多
Muon spin relaxation/rotation(μSR) is a vital technique for probing the superconducting gap structure, pairing symmetry and time reversal symmetry breaking, enabling an understanding of the mechanisms behind the unco...Muon spin relaxation/rotation(μSR) is a vital technique for probing the superconducting gap structure, pairing symmetry and time reversal symmetry breaking, enabling an understanding of the mechanisms behind the unconventional superconductivity of cuprates and Fe-based high-temperature superconductors, which remain a puzzle. Very recently double layered Fe-based superconductors having quasi-2 D crystal structures and Cr-based superconductors with a quasi-1D structure have drawn considerable attention. Here we present a brief review of the characteristics of a few selected Fe-and Cr-based superconducting materials and highlight some of the major outstanding problems, with an emphasis on the superconducting pairing symmetries of these materials. We focus on μSR studies of the newly discovered superconductors ACa_2Fe_4As_4F_2(A = K, Rb, and Cs), ThFeAsN, and A_2Cr_3As_3(A = K, Cs), which were used to determine the superconducting gap structures, the presence of spin fluctuations, and to search for time reversal symmetry breaking in the superconducting states. We also briefly discuss the results of μSR investigations of the superconductivity in hole and electron doped BaFe_2As_2.展开更多
C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invari...C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invariant, but line width of the methylene (-CH2-) carbon increases remarkably, and its NOE factor decreases sharply. This implies that the long-range segmental motion is hindered, and saturated tertiary carbon (-C H- ) is formed during crosslinking of ets 1,4-polybutadiene.展开更多
文摘We have analytically derived the relaxation function for one-dimensional disordered complex systems in terms of autocorrelation function of fractal time random walk by using operator formalism. We have shown that the relaxation function has stretched exponential, i.e. the Kohlrausch-Williams-Watts character for a fractal time random walk process.
基金supported by the National Natural Science Foundation of China(Grant No.11874320)the National Key Research and Development Program of China(Grant No.2017YFA0303100)+2 种基金the Royal Society of London for the UK-China Newton funding and CMPC-STFC(Grant No.CMPC-09108)the DST India,for Inspire Faculty Research(Grant No.DST/INSPIRE/04/2015/000169)and UK-India Newton funding
文摘Muon spin relaxation/rotation(μSR) is a vital technique for probing the superconducting gap structure, pairing symmetry and time reversal symmetry breaking, enabling an understanding of the mechanisms behind the unconventional superconductivity of cuprates and Fe-based high-temperature superconductors, which remain a puzzle. Very recently double layered Fe-based superconductors having quasi-2 D crystal structures and Cr-based superconductors with a quasi-1D structure have drawn considerable attention. Here we present a brief review of the characteristics of a few selected Fe-and Cr-based superconducting materials and highlight some of the major outstanding problems, with an emphasis on the superconducting pairing symmetries of these materials. We focus on μSR studies of the newly discovered superconductors ACa_2Fe_4As_4F_2(A = K, Rb, and Cs), ThFeAsN, and A_2Cr_3As_3(A = K, Cs), which were used to determine the superconducting gap structures, the presence of spin fluctuations, and to search for time reversal symmetry breaking in the superconducting states. We also briefly discuss the results of μSR investigations of the superconductivity in hole and electron doped BaFe_2As_2.
文摘C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invariant, but line width of the methylene (-CH2-) carbon increases remarkably, and its NOE factor decreases sharply. This implies that the long-range segmental motion is hindered, and saturated tertiary carbon (-C H- ) is formed during crosslinking of ets 1,4-polybutadiene.
