Conductance of a spin-1 quantum dot: The two-stage Kondo effect

Posazhennikova, Anna; Bayani, B.; Coleman, Piers

doi:10.1103/physrevb.75.245329

Cited by 34 publications

(54 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2c). Because the Kondo effect strongly depends on the coupling between the localized spin and the conducting electrons, a reduced molecular spin state directly contributes to the suppression of the Kondo effect (Supplementary Section 4)2728. A schematics of manipulation of the molecular Kondo effect by hydrogen adsorption and desorption is illustrated in Fig.…”

Section: Discussionmentioning

confidence: 99%

Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption

Liu

Yang

Jiang

et al. 2013

Sci Rep

123

142

View full text Add to dashboard Cite

The reversible control of a single spin of an atom or a molecule is of great interest in Kondo physics and a potential application in spin based electronics. Here we demonstrate that the Kondo resonance of manganese phthalocyanine molecules on a Au(111) substrate have been reversibly switched off and on via a robust route through attachment and detachment of single hydrogen atom to the magnetic core of the molecule. As further revealed by density functional theory calculations, even though the total number of electrons of the Mn ion remains almost the same in the process, gaining one single hydrogen atom leads to redistribution of charges within 3d orbitals with a reduction of the molecular spin state from S = 3/2 to S = 1 that directly contributes to the Kondo resonance disappearance. This process is reversed by a local voltage pulse or thermal annealing to desorb the hydrogen atom.

show abstract

Section: Discussionmentioning

confidence: 99%

Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption

Liu

Yang

Jiang

et al. 2013

Sci Rep

123

142

View full text Add to dashboard Cite

show abstract

“…We remind that the coupling between the even and odd channels is facilitated by a ferromagnetic interaction which emerges, being however irrelevant in the intermediate coupling regime. Thus, the differential conductance does reach a maximum G/G 0 ≈1 with a characteristic hump [23], [37] at the intermediate coupling regime. Corresponding corrections (deviation of the conductance at the top of the hump from the unitary limit G 0 =2e 2 /h) can be calculated with logarithmic accuracy |δG/G 0 |∝1/ ln 2 (T e K /T o K ) [1], [44] (see also review [21] and [37] for details).…”

Section: Intermediate Coupling Regimementioning

confidence: 96%

“…The description of the FL transport coefficients in the strong coupling regime (C) at the second stage of the screening is the central result of the paper. many years [19,37].…”

Section: Introductionmentioning

confidence: 99%

Two-color Fermi-liquid theory for transport through a multilevel Kondo impurity

et al. 2018

View full text Add to dashboard Cite

We consider a quantum dot with K≥2 orbital levels occupied by two electrons connected to two electric terminals. The generic model is given by a multi-level Anderson Hamiltonian. The weakcoupling theory at the particle-hole symmetric point is governed by a two-channel S=1 Kondo model characterized by intrinsic channels asymmetry. Based on a conformal field theory approach we derived an effective Hamiltonian at a strong-coupling fixed point. The Hamiltonian capturing the low-energy physics of a two-stage Kondo screening represents the quantum impurity by a two-color local Fermi-liquid. Using non-equilibrium (Keldysh) perturbation theory around the strong-coupling fixed point we analyse the transport properties of the model at finite temperature, Zeeman magnetic field and source-drain voltage applied across the quantum dot. We compute the Fermi-liquid transport constants and discuss different universality classes associated with emergent symmetries. arXiv:1802.00407v3 [cond-mat.mes-hall]

show abstract

“…The result is that the two unpaired spins are screened via Kondo screening channels with a very different energy scale and, thus, Kondo temperature [17]. Such a scheme suggests an underscreened spin if the experimental temperature lies between the Kondo temperatures of each screening channels [30,31].…”

mentioning

confidence: 99%

Reversible Change of the Spin State in a Manganese Phthalocyanine by Coordination of CO Molecule

et al. 2012

View full text Add to dashboard Cite

We show that the magnetic state of individual manganese phthalocyanine (MnPc) molecules on a Bi(110) surface is modified when the Mn2þ center coordinates to CO molecules adsorbed on top. Using scanning tunneling spectroscopy we identified this change in magnetic properties from the broadening of a Kondo-related zero-bias anomaly when the CO-MnPc complex is formed. The original magnetic state can be recovered by selective desorption of individual CO molecules. First principles calculations show that the CO molecule reduces the spin of the adsorbed MnPc from S ¼ 1 to S ¼ 1=2 and strongly modifies the respective screening channels, driving a transition from an underscreened Kondo state to a state of mixed valence. DOI: 10.1103/PhysRevLett.109.147202 PACS numbers: 75.20.Hr, 68.37.Ef, 82.37.Gk, 68.43.Bc Control over the magnetic moment of a molecule and its interaction with a substrate is a key issue in the emerging field of molecular spintronics [1]. In metal-phthalocyanines and metal-porphyrins the metal center is usually coordinatively unsaturated and presents a local reactive site, which opens a unique possibility of controlling the magnetic moment in situ by external chemical stimuli [2][3][4][5][6][7][8]. The axial coordination of small molecules like CO, NO or O 2 to those complexes substantially alters their electronic properties, which has led to a successful implementation of phthalocyanines and porphyrins in gas sensors [9,10]. Studies specifically addressing the magnetic state are, however, scarce. Only recently it has been shown that the attachment of a NO molecule to a cobalt-tetraphenylporphyrin (CoTPP) quenches its spin due to the oxidation process [6]. The general picture is however more complicated, as the chemical bond to the reactant molecule causes the redistribution of charge in the d orbitals of the metal center and modifies the ligand field of the metal ion. This has critical consequences for the magnetic ground state of the complex [7,8]. On metal surfaces, the formation of a new ligand bond may additionally alter the hybridization of molecular and substrate states, thus affecting the electronic and magnetic coupling of the metal ion to the substrate [3][4][5]. Understanding the response of these effects to the change in chemical coordination is crucial to gain full control over the functionality of the magnetic system.Here, we show that the magnetic moment of a manganese phthalocyanine (MnPc) molecule [see Fig. 1(a)] on a Bi(110) surface is reduced when coordinated to a CO molecule. Using a combination of a low temperature scanning tunneling microscopy (STM) and density functional theory (DFT) we find, first, that the spin of the MnPc molecule is reduced from S ¼ 3=2 to S ¼ 1 upon adsorption and, second, that CO further reduces the spin of the MnPc from S ¼ 1 to S ¼ 1=2. The change in the magnetic ground state upon CO attachment is detected by the broadening of a characteristic zero-bias anomaly (ZBA). We interpret this broadening as a transition from a Kondo regime, for the bare MnPc on...

show abstract

Conductance of a spin-1 quantum dot: The two-stage Kondo effect

Cited by 34 publications

References 22 publications

Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption

Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption

Two-color Fermi-liquid theory for transport through a multilevel Kondo impurity

Reversible Change of the Spin State in a Manganese Phthalocyanine by Coordination of CO Molecule

Contact Info

Product

Resources

About