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Luttinger liquid superlattices: realization of gapless insulating phases

J. Silva-Valencia·E. Miranda·Raimundo R. dos Santos
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Abstract

We investigate Luttinger Liquid superlattices, a periodic structure composed of two kinds of one-dimensional systems of interacting electrons. We calculate several properties of the low-energy sector: the effective charge and spin velocities, the compressibility, various correlation functions, the Landauer conductance and the Drude weight. The low-energy properties are subsumed into effective parameters, much like homogeneous one-dimensional systems. A generic result is the weighted average nature of these parameters, in proportion to the spatial extent of the underlying subunits, pointing to the possibility of ``engineered'' structures. As a specific realization, we consider a one-dimensional Hubbard superlattice, which consists of a periodic arrangement of two long Hubbard chains with different coupling constants and different hopping amplitudes. This system exhibits a rich phase diagram with several phases, both metallic and insulating. We have found that gapless insulating phases are present over a wide range of parameters.

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J. Silva-Valencia, E. Miranda, Raimundo R. dos Santos. 2002-04-24. Luttinger liquid superlattices: realization of gapless insulating phases. https://doi.org/10.1103/physrevb.65.115115

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