Realistic quantum critical point in one-dimensional two-impurity models
Abstract
We show that the two-impurity Anderson model exhibits an additional quantum critical point at infinitely many specific distances between both impurities for an inversion symmetric one-dimensional dispersion. Unlike the quantum critical point previously established, it is robust against particle-hole or parity symmetry breaking. The quantum critical point separates a spin doublet from a spin singlet ground state and is, therefore, protected. A finite single-particle tunneling or an applied uniform gate voltage will drive the system across the quantum critical point. The discriminative magnetic properties of the different phases cause a jump in the spectral functions at low temperature, which might be useful for future spintronics devices. A local parity conservation will prevent the spin-spin correlation function from decaying to its equilibrium value after spin manipulations.
Cite
@article{arxiv.1609.09750,
title = {Realistic quantum critical point in one-dimensional two-impurity models},
author = {Benedikt Lechtenberg and Fabian Eickhoff and Frithjof B. Anders},
journal= {arXiv preprint arXiv:1609.09750},
year = {2018}
}