A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To...A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To explore the pressure-induced evolution of the magnetism and Fermi surface of the heavy fermion antiferromagnet Yb Pt Bi, we performed tunnel diode oscillator based measurements under pressure at low temperatures in high magnetic fields. Our results reveal that the magnetic order strengthens and the Fermi surface shrinks as the pressure increases, which are consistent with typical observations for Yb-based heavy fermion compounds. In addition, an anomalous change in the quantum oscillation amplitudes is observed above 1.5 GPa, and determining the origin requires further study.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
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0303100)the National Natural Science Foundation of China(Grant Nos.11974306 and 12034017)the Natural Science Foundation of Zhejiang Province(Grant No.2021C01002)。
文摘A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To explore the pressure-induced evolution of the magnetism and Fermi surface of the heavy fermion antiferromagnet Yb Pt Bi, we performed tunnel diode oscillator based measurements under pressure at low temperatures in high magnetic fields. Our results reveal that the magnetic order strengthens and the Fermi surface shrinks as the pressure increases, which are consistent with typical observations for Yb-based heavy fermion compounds. In addition, an anomalous change in the quantum oscillation amplitudes is observed above 1.5 GPa, and determining the origin requires further study.
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.
