Kondo-Transport Spectroscopy of Single Molecule Magnets

Romeike, C.; Wegewijs, M. R.; Hofstetter, Walter; Schoeller, Herbert

doi:10.1103/physrevlett.97.206601

Cited by 99 publications

(48 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the properties of SMMs and the Kondo effect can be modulated with an external magnetic field. [7] Here we present the results of studies on the SMM properties of a new Tb III triple-decker phthalocyaninate derivative, [Tb 2 A C H T U N G T R E N N U N G (obPc) 3 ] (1; obPc = dianion of 2,3,9,10,16,17,23,24-octabutoxyphthalocyanine). The relationships among the molecular structure, ligand-field, ground-state, and SMM properties in a direct current (dc) magnetic field are discussed.…”

Section: Wolfgang Wernsdorfermentioning

confidence: 99%

Magnetic Relaxation of Single‐Molecule Magnets in an External Magnetic Field: An Ising Dimer of a Terbium(III)–Phthalocyaninate Triple‐Decker Complex

Katoh¹,

Kajiwara²,

Nakano³

et al. 2010

Chemistry A European J

137

151

View full text Add to dashboard Cite

Section: Wolfgang Wernsdorfermentioning

confidence: 99%

Magnetic Relaxation of Single‐Molecule Magnets in an External Magnetic Field: An Ising Dimer of a Terbium(III)–Phthalocyaninate Triple‐Decker Complex

Katoh¹,

Kajiwara²,

Nakano³

et al. 2010

Chemistry A European J

137

151

View full text Add to dashboard Cite

“…In addition, the detection of a Kondo state by using scanning tunnelling microscope (STM) should contribute to the understanding of localized spins. However, despite extensive experimental and theoretical studies1920, little is known about the Kondo effect in SMMs.…”

mentioning

confidence: 99%

Observation and electric current control of a local spin in a single-molecule magnet

et al. 2011

View full text Add to dashboard Cite

In molecular spintronics, the spin state of a molecule may be switched on and off by changing the molecular structure. Here, we switch on and off the molecular spin of a double-decker bis(phthalocyaninato)terbium(III) complex (TbPc2) adsorbed on an Au(111) surface by applying an electric current via a scanning tunnelling microscope. The dI/dV curve of the tunnelling current recorded onto a TbPc2 molecule shows a Kondo peak, the origin of which is an unpaired spin of a π-orbital of a phthalocyaninato (Pc) ligand. By applying controlled current pulses, we could rotate the upper Pc ligand in TbPc2, leading to the disappearance and reappearance of the Kondo resonance. The rotation shifts the molecular frontier-orbital energies, quenching the π-electron spin. Reversible switching between two stable ligand orientations by applying a current pulse should make it possible to code information at the single-molecule level.

show abstract

“…4 for S = 7/2, c.f. [4]. Finally, we mention the possibility that the Kondo coupling can not connect two TR-invariant subsets which leads to a complete vanishing of the effective coupling constants j x,y = 0.…”

mentioning

confidence: 99%

“…Recently, a single molecule magnet (Mn 12 ) was trapped in a nanogap [2,3] and fingerprints of the molecular spin were observed in electron transport. Furthermore, transport fingerprints of QTM were predicted [4] when the individual excitations can be resolved by the temperature. Using easy-axis anisotropy for magnetic device operation was also proposed [5].…”

mentioning

confidence: 99%

Quantum-Tunneling-Induced Kondo Effect in Single Molecular Magnets

et al. 2006

Self Cite

View full text Add to dashboard Cite

We consider transport through a single-molecule magnet strongly coupled to metallic electrodes. We demonstrate that for half-integer spin of the molecule electron-and spin-tunneling cooperate to produce both quantum tunneling of the magnetic moment and a Kondo effect in the linear conductance. The Kondo temperature depends sensitively on the ratio of the transverse and easyaxis anisotropies in a non-monotonic way. The magnetic symmetry of the transverse anisotropy imposes a selection rule on the total spin for the occurrence of the Kondo effect which deviates from the usual even-odd alternation.PACS numbers: 72.10. Fk, 75.10.Jm, 75.30.Gw, 75.60.Jk Introduction. Single-molecule magnets (SMMs) such as Mn 12 or Fe 8 have been the focus of intense experimental and theoretical investigation [1]. These molecules are characterized by a large spin (S > 1/2), easy-axis and transverse anisotropies, and weak intermolecular interaction. Molecular-crystal properties are due to an ensemble of single molecules and exhibit quantum tunneling of magnetization (QTM) on a mesoscopic scale. Recently, a single molecule magnet (Mn 12 ) was trapped in a nanogap [2,3] and fingerprints of the molecular spin were observed in electron transport. Furthermore, transport fingerprints of QTM were predicted [4] when the individual excitations can be resolved by the temperature. Using easy-axis anisotropy for magnetic device operation was also proposed [5]. These works focused on the regime where single electrons charge and discharge the molecule through weak tunneling. In this Letter we investigate linear transport through a half-integer spin SMM deep inside the blockade regime [6] where the charge on the molecule remains fixed. A strong tunnel-coupling to the metallic electrodes induces spin fluctuations and allows the magnetic moment to tunnel. This is remarkable, since for an isolated SMM with half-integer S this is forbidden by time-reversal (TR) symmetry. At the same time, the resonant spinscattering allows electrons to pass through the SMM: the Kondo effect for transport [7,8] results in a zero bias conductance anomaly that has been studied experimentally in many systems with small spins (e.g. quantum dots [9,10,11,12,13] and single molecules [14,15]). Such an effect is unexpected in SMMs because the S > 1/2 underscreened Kondo effect is suppressed by the easyaxis anisotropy barrier which freezes the spin along the easy axis. However, we find that even a weak transverse anisotropy induces a pseudo-spin-1/2 Kondo effect. The corresponding Kondo temperature is experimentally accessible due to a compensation by the large value of the physical spin S. We perform a scaling analysis [16] for the effective pseudo-spin-1/2 model and verify the results by a non-perturbative numerical renormalization group (NRG) calculation [17,18] for the full large-spin Hamiltonian.Model. We consider SMMs which can be described by the following minimal model in the limit of strong tunnel-

show abstract

Kondo-Transport Spectroscopy of Single Molecule Magnets

Cited by 99 publications

References 19 publications

Magnetic Relaxation of Single‐Molecule Magnets in an External Magnetic Field: An Ising Dimer of a Terbium(III)–Phthalocyaninate Triple‐Decker Complex

Magnetic Relaxation of Single‐Molecule Magnets in an External Magnetic Field: An Ising Dimer of a Terbium(III)–Phthalocyaninate Triple‐Decker Complex

Observation and electric current control of a local spin in a single-molecule magnet

Quantum-Tunneling-Induced Kondo Effect in Single Molecular Magnets

Contact Info

Product

Resources

About