کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1543639 | 1512865 | 2016 | 17 صفحه PDF | دانلود رایگان |
• Persistent current in 1D Hubbard ring is critically analyzed.
• Interplay between e–e interaction, long-range hopping and disorder is discussed.
• Comparison between exact diagonalization and MF theory is given.
• Significant enhancement of current takes place in a disordered ring.
• Scaling behavior of current is investigated.
The interplay between Hubbard interaction, long-range hopping and disorder on persistent current in a mesoscopic one-dimensional conducting ring threaded by a magnetic flux ϕ is analyzed in detail. Two different methods, exact numerical diagonalization and Hartree–Fock mean field theory, are used to obtain numerical results from the many-body Hamiltonian. The current in a disordered ring gets enhanced as a result of electronic correlation and it becomes more significant when contributions from higher order hoppings, even if they are too small compared to nearest-neighbor hopping, are taken into account. Certainly this can be an interesting observation in the era of long-standing controversy between theoretical and experimental results of persistent current amplitudes. Along with these we also find half-flux quantum periodic current for some typical electron fillings and kink-like structures at different magnetic fluxes apart from ϕ=0ϕ=0 and ±ϕ0/2±ϕ0/2. The scaling behavior of current is also discussed for the sake of completeness of our present analysis.
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 84, October 2016, Pages 118–134