Spin fluctuation effects on the conductance through a single Pd atom contact

Romero, Marcelo Ariel; Gómez-Carrillo, S C; Bolcatto, P. G.; Goldberg, E. C.

doi:10.1088/0953-8984/21/21/215602

Cited by 8 publications

(9 citation statements)

References 33 publications

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“…One possible approach for this task would be to perform equations of motion for the different Keldysh Green functions, 86 truncate them with some approximation and take the limit ∆ L , ∆ R → 0. However, the presence of both interactions and the hopping terms renders the process very cumbersome.…”

Section: A the Atomic Limitmentioning

confidence: 99%

Heat current across a capacitively coupled double quantum dot

Aligia¹,

Daroca²,

Arrachea³

et al. 2020

Phys. Rev. B

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We study the heat current through two capacitively coupled quantum dots coupled in series with two conducting leads in the spinless case (valid for a high applied magnetic field). Our results are also valid for the heat current through a single quantum dot with strongly ferromagnetic leads pointing in opposite directions (so that the electrons with given spin at the dot can jump only to one lead) or through a quantum dot with two degenerate levels with destructive quantum interference and high magnetic field. Although the charge current is always zero, the heat current is finite when the interdot Coulomb repulsion is taken into account due to many-body effects. We generalize previous results for high temperatures and particular parameters obtained by Yadalam and Harbola [Phys. Rev. B 99, 195449 (2019)]. In particular we consider temperatures for which an orbital Kondo regime takes place. In contrast to previous results, we find that the heat current is finite even for U → ∞. In the Kondo regime, for temperatures much less than the Kondo energy scale, we obtain that the dependence of the thermal current with the temperature difference ∆T is ∼ (∆T ) 4 when the cold lead is at TC ≪ ∆T , and linear in ∆T if TC ≫ ∆T . For large TC the current saturates. As a function of Coulomb strength U , for high ∆T and TC = 0, the charge current has a maximum for U ∼ 3∆T and decreases with increasing U reaching a finite value for U → ∞. We also consider the case of different energy levels of the dots for which the device has rectifying properties.

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Section: A the Atomic Limitmentioning

confidence: 99%

Heat current across a capacitively coupled double quantum dot

Aligia¹,

Daroca²,

Arrachea³

et al. 2020

Phys. Rev. B

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“…In the case of an infinite value of the electronic intrasite repulsion U, this kind of formalism has proved to be successful for describing the charge exchange between a surface and the correlated states of an atom. [28][29][30][31] The finite U treatment presented in this work also allows us to reproduce the weak and strong coupling limits found in the transmission phase shift of a dot measured by Aharonov-Bohm interferometry. [32][33][34][35] The potentiality of this calculation for describing dynamical processes such as the collision between atoms and surfaces is tested in the simple model of a many-body system consisting of an adatom attached to a substrate of three atoms.…”

Section: Introductionmentioning

confidence: 94%

“…[17][18][19] Levy Yeyati et al proposed an interesting extension of the second-order self-energy associated with the Coulomb interaction to high values of U. 20 In the case of a finite but large electronic repulsion, equation of motion ͑EOM͒ 2, [10][11][12][13][14][15][21][22][23][24][25][26][27] offers an easy way of handling realistic models for the atom-surface interacting system in and out of equilibrium, 28,29 and it is an appropriate method when time-dependent interactions are involved. 30,31 In the case of the single impurity Anderson model, the equation of motion of the single-particle Green's function gives rise to an infinite hierarchy of equations of motion for higher-order Green's functions.…”

Section: Introductionmentioning

confidence: 99%

Effective treatment of charge and spin fluctuations in dynamical and static atom-surface interactions

2009

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In this work we introduce a formalism that provides a good description of the correlated charge states of an atom interacting statically or dynamically with a metal surface, including realistic features of the atom-surface system. Our treatment of the Anderson impurity with an intrasite finite repulsion is based on the use of a projection operator technique and the application of the equation of motion method. The specific case of charge state configurations having zero, one, and two valence electrons of atoms with s-type valence orbital is discussed in this work. Static properties, such as the average occupation and the local density of states at the atom site and dynamical charge fractions in atom scattering processes, are compared with exact calculations and also with other existing approximations. Our treatment of the finite electronic repulsion at the atom site also reproduces satisfactorily the experimental behavior of the transmission phase shift of a dot measured by Aharonov-Bohm interferometry in both weak and strong coupling limits.

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“…We solve the ionic Hamiltonian by means of Green functions calculated using the equation of motion (EOM) method, closing the system of equations in a second order in the atom-band coupling term [34][35][36]. This method has been used in several systems where many-body effects become relevant [33,34,[37][38][39][40][41]. The introduction of the Hamiltonian and its solution are presented in Section II.…”

Section: Introductionmentioning

confidence: 99%

Surface states influence in the conductance spectra of Co adsorbed on Cu(111)

Tacca,

Jacob,

Goldberg

2021

Preprint

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We calculate the conductance spectra of a Co atom adsorbed on Cu(111), considering the Co 3d orbitals within a correlated multiple configurations model interacting through the substrate band with the Co 4s orbital, which is treated in a mean-field like approximation. By symmetry, only the d z 2 orbital couples with the s orbital through the Cu bands, and the interference between both conduction channels introduces a zero-bias anomaly in the conductance spectra. We find that, while the Kondo resonance is mainly determined by the interaction of the Co d orbitals with the bulk states of the Cu(111) surface, a proper description of the contribution given by the coupling with the localized surface states to the Anderson widths is crucial to describe the interference line shape. We find that the coupling of the Co 4s orbital with the Shockley surface states is responsible of two main features observed in the measured conductance spectra, the dip shape around the Fermi energy and the resonance structure at the surface state low band edge.

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Spin fluctuation effects on the conductance through a single Pd atom contact

Cited by 8 publications

References 33 publications

Heat current across a capacitively coupled double quantum dot

Heat current across a capacitively coupled double quantum dot

Effective treatment of charge and spin fluctuations in dynamical and static atom-surface interactions

Surface states influence in the conductance spectra of Co adsorbed on Cu(111)

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