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Ground state structure and conductivity of quantum wires of infinite length and finite width

Francesc Malet·Marti Pi·Manuel Barranco·Enrico Lipparini
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Abstract

We have studied the ground state structure of quantum strips within the local spin-density approximation, for a range of electronic densities between $\sim$ 5$\times10^4$ and 2$\times10^6$ cm$^{-1}$ and several strengths of the lateral confining potential. The results have been used to address the conductance $G$ of quantum strips. At low density, when only one subband is occupied, the system is fully polarized and $G$ takes a value which is close to 0.7(2e$^2/h$), decreasing with increasing electron density in agreement with experiments. At higher densities the system becomes paramagnetic and $G$ takes a value near (2e$^2/h$), showing a similar decreasing behaviour with increasing electron density. In both cases, the physical parameter that determines the value of the conductance is the ratio $K/K_0$ of the compressibility of the system over the free one.

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Francesc Malet, Marti Pi, Manuel Barranco, Enrico Lipparini. 2005-11-15. Ground state structure and conductivity of quantum wires of infinite length and finite width. https://doi.org/10.1103/physrevb.72.205326

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