In this study, we investigate the tunneling conductance at a finite temperature in a normal metal/ferromagnetic superconductor nano-junction where the ferromagnetic superconductor （FS） is in three different cooper p...In this study, we investigate the tunneling conductance at a finite temperature in a normal metal/ferromagnetic superconductor nano-junction where the ferromagnetic superconductor （FS） is in three different cooper pairing states： spin singlet s-wave pairing （SWP）, spin triplet opposite spin pairing （OSP）, and spin triplet equal spin pairing （ESP） while including Fermi wave mismatch （FWM） and effective mass mismatch （EMM） in two sides of the nano-junction. We find that the conductance shows clearly different behaviors all depending on the symmetries of cooper pairing in a manner that the conductance spectra shows a gap-like structure, two interior dips structure and zero bias peak for SWP, OSP, and ESP, respectively. Also, the effective FS gap （Δeff） is a linear and decreasing function of exchange field. The slope of （Δeff） versus exchange field for OSP is twice the SWP. Thus, we can determine the spin polarization of N/FS nano-junction based on the dependence of （Δeff） to exchange field.展开更多
Superconductivity （SC） and ferromagnetism （FM） are in general antagonistic, which makes their coexistence very rare. Following our recent discovery of robust coexistence of SC and FM in RbEuFe4As4 （Liu et al. in ...Superconductivity （SC） and ferromagnetism （FM） are in general antagonistic, which makes their coexistence very rare. Following our recent discovery of robust coexistence of SC and FM in RbEuFe4As4 （Liu et al. in Phys Rev B 93：214503, 2016）, here we report another example of such a coexistence in its sister com- pound CsEuFe4As4, synthesized for the first time. The new material exhibits bulk SC at 35.2 K and Eu2＋-spin ferro- magnetic ordering at 15.5 K, demonstrating that it is a new robust ferromagnetic superconductor.展开更多
文摘In this study, we investigate the tunneling conductance at a finite temperature in a normal metal/ferromagnetic superconductor nano-junction where the ferromagnetic superconductor （FS） is in three different cooper pairing states： spin singlet s-wave pairing （SWP）, spin triplet opposite spin pairing （OSP）, and spin triplet equal spin pairing （ESP） while including Fermi wave mismatch （FWM） and effective mass mismatch （EMM） in two sides of the nano-junction. We find that the conductance shows clearly different behaviors all depending on the symmetries of cooper pairing in a manner that the conductance spectra shows a gap-like structure, two interior dips structure and zero bias peak for SWP, OSP, and ESP, respectively. Also, the effective FS gap （Δeff） is a linear and decreasing function of exchange field. The slope of （Δeff） versus exchange field for OSP is twice the SWP. Thus, we can determine the spin polarization of N/FS nano-junction based on the dependence of （Δeff） to exchange field.
基金supported by the National Natural Science Foundation of China (11474252, 90922002 and 11190023)the National Basic Research Program of China (2012CB821404)
文摘Superconductivity （SC） and ferromagnetism （FM） are in general antagonistic, which makes their coexistence very rare. Following our recent discovery of robust coexistence of SC and FM in RbEuFe4As4 （Liu et al. in Phys Rev B 93：214503, 2016）, here we report another example of such a coexistence in its sister com- pound CsEuFe4As4, synthesized for the first time. The new material exhibits bulk SC at 35.2 K and Eu2＋-spin ferro- magnetic ordering at 15.5 K, demonstrating that it is a new robust ferromagnetic superconductor.
