Competition between local potentials and attractive particle-particle interactions in superlattices

Abstract

Naturally occuring or man-made systems displaying periodic spatial modulations of their properties on a nanoscale constitute superlattices. Such modulated structures are important both as prototypes of simple nanotechnological devices and as particular examples of emerging spatial inhomogeneity in interacting many-electron systems. Here we investigate the effect different types of modulation of the system parameters have on the ground-state energy and the charge-density distribution of the system. The superlattices are described by the inhomogeneous attractive Hubbard model, and the calculations are performed by density-functional and density-matrix renormalization group techniques. We find that modulations in local electric potentials are much more effective in shaping the system's properties than modulations in the attractive on-site interaction. This is the same conclusions we previously (Phys. Rev. B 71, 125130) obtained for repulsive interactions, suggesting that it is not an artifact of a specific state, but a general property of modulated structures.

8 pages, 2 figures

References in corpus (10)

• Imaging the granular structure of high-Tc superconductivity in underdoped Bi2Sr2CaCu2O8+x
• Density-functionals not based on the electron gas: Local-density approximation for a Luttinger liquid
• Bethe-Ansatz density-functional theory of ultracold repulsive fermions in one-dimensional optical lattices
• What can Mott insulators teach us about density-functional theory (and vice versa)?
• Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
• Phase diagram of harmonically confined one-dimensional fermions with attractive and repulsive interactions
• Effects of nanoscale spatial inhomogeneity in strongly correlated systems
• Charge-density waves in one-dimensional Hubbard superlattices
• Multiperiodic magnetic structures in Hubbard superlattices
• Luttinger liquid superlattices

Cited by in corpus (4)

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• Entanglement in spatially inhomogeneous many-fermion systems
• Density-functional theory approach to the thermodynamics of the harmonically confined one-dimensional Hubbard model
• Effect of spatial inhomogeneity on the mapping between strongly interacting fermions and weakly interacting spins