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Strongly renormalized quasi-two-dimensional electron gas in a heterostructure with correlation effects

Andreas Rüegg·Sebastian Pilgram·Manfred Sigrist
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Abstract

We present aspects of strong electron correlation in a model of a BI/M/BI heterostructure where BI is a band insulator and M can be tuned from a metal to a Mott insulator by varying the on-site repulsion. An effective one-dimensional Schroedinger equation for the low-energy part is derived in the framework of the Kotliar-Ruckenstein slave-boson mean-field theory and solved self-consistently for a wide range of the on-site interaction strength and of the width of the sandwiched material M. In the strongly interacting limit coherent quasiparticles responsible for metallic behavior are confined to a relatively narrow region near the interfaces where they form a quasi-two-dimensional electron gas. Due to the lack of spatial homogeneity these quasiparticles intrinsically obtain a nontrivial dependence on the transverse momentum which for example enters the low-energy behavior of the optical conductivity.

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Andreas Rüegg, Sebastian Pilgram, Manfred Sigrist. 2007-01-26. Strongly renormalized quasi-two-dimensional electron gas in a heterostructure with correlation effects. https://doi.org/10.1103/physrevb.75.195117

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