Kondo effect in Lieb's ferrimagnetic system on the T-shaped bipartite lattice

TL;DR

This paper investigates the Kondo effect in a minimal Lieb ferrimagnetic system on a T-shaped bipartite lattice, revealing how magnetic moments are screened and conductance properties are affected, with implications for quantum entanglement.

Contribution

It provides a theoretical analysis of the Kondo effect in Lieb's ferrimagnetic system, highlighting the two-step screening process and conductance behavior, which is a novel insight into this minimal ferrimagnetic model.

Findings

Magnetic moment S=1 is screened in two steps by the Kondo effect.

Series conductance g_s is strongly suppressed to near zero.

Parallel conductance g_p reaches the maximum value of approximately 4e^2/h.

Abstract

The minimal ferrimagnetism by Lieb's theorem emerges on the T-shaped bipartite lattice composed of four sites, which can be realized experimentally, just as Nagaoka ferromagnetism has been demonstrated experimentally using a quartet quantum-dot(J.P.Dehollain et al., Nature 579, 528 (2020).). In this paper, the Kondo effect on this ferrimagnetism is theoretically studied. The magnetic moment $S=1$ is screened in two steps by the Kondo effect and the series conductance $g_{s}$ is strongly suppressed to $g_{s}\simeq 0$, while the parallel conductance $g_{p}$ has the maximum value $g_{p}\simeq 4e^{2}/h$. The robustness of these properties against a parameter change toward reducing the Lieb's ferrimagnetism is also discussed, showing the scenarios for entanglement of the degrees of freedom toward the ground state.