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

N. A. Lima·A. L. Malvezzi·K. Capelle
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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.

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N. A. Lima, A. L. Malvezzi, K. Capelle. 2006-11-17. Competition between local potentials and attractive particle-particle interactions in superlattices. https://doi.org/10.1016/j.ssc.2007.03.057

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