Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics Condensed Matter

The single impurity problem with interactions in two dimensions

D. Schmeltzer, Richard Berkovits, M. Kaveh, Eugene Kogan

Published Sep 28, 1998• 1 citation
Publisher

Abstract

We study the behaviour of a single impurity potential within a combined method of renormalization group and bosonization in two dimensions. For repulsive interactions the backscattering components of the impurity potential are enhanced with respect to the other angles. We estimate the corrections to the conductivity as a function of . For we obtain similar results as in the non-interacting case. At finite temperatures, we obtain results controlled by the interactions. Here we identify a range of temperatures in which the conductivity increases with the lowering of the temperature.

DOI
10.1088/0953-8984/10/38/001

Related papers

Renormalization of impurity scattering in one-dimensional interacting electron systems in magnetic field

Takashi Hikihara, Akira Furusaki, К. А. Матвеев

We study the renormalization of a single impurity potential in one-dimensional interacting electron systems in the presence of magnetic field. Using the bosonization technique and Bethe ansatz solutions, we determine the renormalization group flow diagram for the amplitudes of scattering of up- and down-spin electrons by the impurity in a quantum wire at low electron density and in the Hubbard model at less than half filling. In the absence of magnetic field the repulsive interactions are known to enhance backscattering and make the impurity potential impenetrable in the low-energy limit. On the contrary, we show that in a strong magnetic field the interaction may suppress the backscattering of majority-spin electrons by the impurity potential in the vicinity of the weak-potential fixed point. This implies that in a certain temperature range the impurity becomes almost transparent for the majority-spin electrons while it is impenetrable for the minority-spin ones. The impurity potential can thus have a strong spin-filtering effect.

arXiv:cond-mat/0412403•Physical Review B•Jul 1, 2005•21 citations

Renormalization-group analysis of the one-dimensional extended Hubbard model with a single impurity

Sabine Andergassen, Tilman Enss, V. Meden +3 more

We analyze the one-dimensional extended Hubbard model with a single static impurity by using a computational technique based on the functional renormalization group. This extends previous work for spinless fermions to spin-$1∕2$ fermions. The underlying approximations are devised for weak interactions and arbitrary impurity strengths, and have been checked by comparing with density-matrix renormalization-group data. We present results for the density of states, the density profile, and the linear conductance. Two-particle backscattering leads to striking effects, which are not captured if the bulk system is approximated by its low-energy fixed point, the Luttinger model. In particular, the expected decrease of spectral weight near the impurity and of the conductance at low energy scales is often preceded by a pronounced increase, and the asymptotic power laws are modified by logarithmic corrections.

arXiv:cond-mat/0509021•Physical Review B•Jan 26, 2006•48 citations

Persistent current in a two-chain Hubbard model with impurities

弘之 森

The interplay between impurities and interactions is studied in the gapless phase in a two-chain Hubbard model in order to see how the screening of impurity potentials due to repulsive interactions in a single-chain model will be changed by increasing the number of channels. Renormalization-group calculations show that charge stiffness, and hence persistent current, of the two-chain model are less enhanced by interactions than in the single-chain case.

arXiv:cond-mat/9804265•Physical review. B, Condensed matter•Aug 15, 1998•1 citation

Conductance of quantum wires: A numerical study of effects of an impurity and interactions

Amit Agarwal, Diptiman Sen

We use the nonequilibrium Green's function formalism and a self-consistent Hartree-Fock approximation to numerically study the effects of a single impurity and interactions between the electrons (with and without spin) on the conductance of a quantum wire. We study how the conductance varies with the wire length, the temperature, and the strengths of the impurity and interactions. The numerical results for the dependence of the conductance on the wire length and temperature are compared with the results obtained from a renormalization group analysis based on the Hartree-Fock approximation. For the spin-$1∕2$ model with a repulsive on-site interaction or the spinless model with an attractive nearest neighbor interaction, we find that the conductance increases with increasing wire length or decreasing temperature. This can be explained using the Born approximation in scattering theory. For a strong impurity, the conductance is significantly different for a repulsive and an attractive impurity; this is due to the existence of a bound state in the latter case. In general, the large density deviations close to the impurity have an appreciable effect on the conductance at short distances which is not captured by the renormalization group equations.

arXiv:cond-mat/0507097•Physical Review B•Jan 30, 2006•15 citations

A Kondo Impurity in One-Dimensional Correlated Conduction Electrons

Xiaoqun Wang

A spin-1/2 magnetic impurity coupled to a one-dimensional correlated electron system have been studied by applying the density renormalization group method. The Kondo temperature is substantially enhanced by strong repulsive interactions in the chain, but it changes non-monotonically in the case of electron attraction. The magnetization of the impurity at zero-temperature shows local Fermi liquid behavior.

arXiv:cond-mat/9705302•Modern Physics Letters B•Jul 20, 1998•8 citations

A Kondo impurity in one-dimensional correlated conduction electrons.

Wang, X.

A spin-1/2 magnetic impurity coupled to a one-dimensional correlated electron system have been studied by applying the density renormalization group method. The Kondo temperature is substantially enhanced by strong repulsive interactions in the chain, but changes non-monotonically in the case of electron attraction. The magnetization of the impurity at zero- temperature shows local Fermi liquid behavior.

•Jan 1, 1998•2 citations
We study the behaviour of a single impurity potential within a combined method of renormalization group and bosonization in two dimensions. For repulsive interactions the backscattering components of the impurity potential are enhanced with respect to the other angles. We estimate the corrections to the conductivity as a function of . For we obtain similar results as in the non-interacting case. At finite temperatures, we obtain results controlled by the interactions. Here we identify a range of temperatures in which the conductivity increases with the lowering of the temperature.
We study the renormalization of a single impurity potential in one-dimensional interacting electron systems in the presence of magnetic field. Using the bosonization technique and Bethe ansatz solutions, we determine the renormalization group flow diagram for the amplitudes of scattering of up- and down-spin electrons by the impurity in a quantum wire at low electron density and in the Hubbard model at less than half filling. In the absence of magnetic field the repulsive interactions are known to enhance backscattering and make the impurity potential impenetrable in the low-energy limit. On the contrary, we show that in a strong magnetic field the interaction may suppress the backscattering of majority-spin electrons by the impurity potential in the vicinity of the weak-potential fixed point. This implies that in a certain temperature range the impurity becomes almost transparent for the majority-spin electrons while it is impenetrable for the minority-spin ones. The impurity potential can thus have a strong spin-filtering effect.
We analyze the one-dimensional extended Hubbard model with a single static impurity by using a computational technique based on the functional renormalization group. This extends previous work for spinless fermions to spin-1∕21∕21∕2 fermions. The underlying approximations are devised for weak interactions and arbitrary impurity strengths, and have been checked by comparing with density-matrix renormalization-group data. We present results for the density of states, the density profile, and the linear conductance. Two-particle backscattering leads to striking effects, which are not captured if the bulk system is approximated by its low-energy fixed point, the Luttinger model. In particular, the expected decrease of spectral weight near the impurity and of the conductance at low energy scales is often preceded by a pronounced increase, and the asymptotic power laws are modified by logarithmic corrections.
We use the nonequilibrium Green's function formalism and a self-consistent Hartree-Fock approximation to numerically study the effects of a single impurity and interactions between the electrons (with and without spin) on the conductance of a quantum wire. We study how the conductance varies with the wire length, the temperature, and the strengths of the impurity and interactions. The numerical results for the dependence of the conductance on the wire length and temperature are compared with the results obtained from a renormalization group analysis based on the Hartree-Fock approximation. For the spin-1∕21∕21∕2 model with a repulsive on-site interaction or the spinless model with an attractive nearest neighbor interaction, we find that the conductance increases with increasing wire length or decreasing temperature. This can be explained using the Born approximation in scattering theory. For a strong impurity, the conductance is significantly different for a repulsive and an attractive impurity; this is due to the existence of a bound state in the latter case. In general, the large density deviations close to the impurity have an appreciable effect on the conductance at short distances which is not captured by the renormalization group equations.