Kondo peak splitting and Kondo dip induced by a local moment

Abstract

Many features like spin-orbit coupling, bias and magnetic fields applied, and so on, can strongly influence the Kondo effect. One of the consequences is Kondo peak splitting. However, Kondo peak splitting led by a local moment has not been investigated systematically. In this research we study theoretically electronic transport through a single-level quantum dot exchange coupled to a local magnetic moment in the Kondo regime. We focus on the Kondo peak splitting induced by an anisotropic exchange coupling between the quantum dot and the local moment, which shows rich splitting behavior. We consider the cases of a local moment with S = 1/2 and S = 1. The longitudinal (z-component) coupling plays a role of multivalued magnetic fields and the transverse (x, y-components) coupling lifts the degeneracy of the quantum dot, both of which account for the fine Kondo peak splitting structures. The inter-level or intra-level transition processes are identified in detail. Moreover, we find a Kondo dip at the Fermi level under the proper parameters. The possible experimental observations of these theoretical results should deepen our understanding of Kondo physics.

Unexpected Zero Bias Conductance Peak on the Topological Semimetal Sb(111) with a Broken Bilayer

“…3(d) shows that at B = 9 T, the ZBCP is still robust, and its width remains around 10 meV by the Lorentzian fit. The absence of peak splitting means the possibility for Kondo effect [12,33] to play a role in inducing the ZBCP is not apparent from the experiment. Otherwise, an energy splitting of ∆E ≈13.4 meV would be expected from Kondo resonance with ∆E = 2gµ B B [34], given g≈12.8 for Sb [25].…”

Local density of states of the interacting resonant level model at zero temperature

“…2 which occur at much larger energy -this is an intrinsic splitting of the low-energy resonant peak. We also emphasise that unlike previous work on the splitting of the resonance peak in the Kondo model [33][34][35][36], this occurs without an external field splitting the energies of the resonant level, or coupling to any other degree of freedom. Another aspect that makes this evolution particularly surprising is that it is not seen in the susceptibility χ = − ∂ d † d /∂ε 0 which remains approximately in Lorenzian shape for all values of interaction [27].…”

Large enhancement of thermoelectric effects in a tunneling-coupled parallel DQD-AB ring attached to one normal and one superconducting lead

“…In the ridged quantum well system very high seeback coefficient and large enhancement of the thermoelectric figure of merit has been predicted in theory [18]. Hence, the thermoelectric properties of QDs, molecules, quantum wires and silicon nanojunctions have attracted a lot of research interest in the experiment [19][20][21][22][23][24][25][26] and in the theory [1,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. In addition, thermoelectric cooling has also received increasing attention, among which cooling by tunneling was observed [42] and optimization of tunneling cooler was also investigated [43].…”