We numerically investigate magnon-mediated spin transport through nonmagnetic metal/ferromagnetic insulator(NM/FI)heterostructures in the presence of Anderson disorder,and discover universal behaviors of the spin cond...We numerically investigate magnon-mediated spin transport through nonmagnetic metal/ferromagnetic insulator(NM/FI)heterostructures in the presence of Anderson disorder,and discover universal behaviors of the spin conductance in both one-dimensional(1D)and 2D systems.In the localized regime,the variance of logarithmic spin conductanceσ2(lnGγ)shows a universal linear scaling with its average(lnGγ),independent of Fermi energy,temperature,and system size in both 1D and 2D cases.In 2D,the competition between disorder-enhanced density of states at the NM/FI interface and disorder-suppressed spin transport leads to a non-monotonic dependence of average spin conductance on the disorder strength.As a result,in the metallic regime,average spin conductance is enhanced by disorder,and a new linear scaling between spin conductance fluctuation rms(GT)and average spin conductance GT is revealed which is universal at large system width.These universal scaling behaviors suggest that spin transport mediated by magnon in disordered 2D NM/FI systems belongs to a new universality class,different from that of charge conductance in 2D normal metal systems.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.12034014 and 12174262).
文摘We numerically investigate magnon-mediated spin transport through nonmagnetic metal/ferromagnetic insulator(NM/FI)heterostructures in the presence of Anderson disorder,and discover universal behaviors of the spin conductance in both one-dimensional(1D)and 2D systems.In the localized regime,the variance of logarithmic spin conductanceσ2(lnGγ)shows a universal linear scaling with its average(lnGγ),independent of Fermi energy,temperature,and system size in both 1D and 2D cases.In 2D,the competition between disorder-enhanced density of states at the NM/FI interface and disorder-suppressed spin transport leads to a non-monotonic dependence of average spin conductance on the disorder strength.As a result,in the metallic regime,average spin conductance is enhanced by disorder,and a new linear scaling between spin conductance fluctuation rms(GT)and average spin conductance GT is revealed which is universal at large system width.These universal scaling behaviors suggest that spin transport mediated by magnon in disordered 2D NM/FI systems belongs to a new universality class,different from that of charge conductance in 2D normal metal systems.
