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Related papers: Valley Kondo Effect in Silicon Quantum Dots

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We study the spin-valley Kondo effect of a silicon quantum dot occupied by $% \mathcal{N}$ electrons, with $\mathcal{N}$ up to four. We show that the Kondo resonance appears in the $\mathcal{N}=1,2,3$ Coulomb blockade regimes, but not in…

Materials Science · Physics 2019-09-04 Shiueyuan Shiau , Robert Joynt

We report measurements consistent with the valley Kondo effect in Si/SiGe quantum dots, evidenced by peaks in the conductance versus source-drain voltage that show strong temperature dependence. The Kondo peaks show unusual behavior in a…

Mesoscale and Nanoscale Physics · Physics 2014-07-04 Mingyun Yuan , R. Joynt , Zhen Yang , Chunyang Tang , D. E. Savage , M. G. Lagally , M. A. Eriksson , A. J. Rimberg

We report on the valley blockade and the multielectron Kondo effect generated by an impurity atom in a silicon nano field effect device. According to the spin-valley nature of tunnelling processes, and consistently with those allowed by the…

Mesoscale and Nanoscale Physics · Physics 2015-09-10 A. Crippa , M. L. V. Tagliaferri , D. Rotta , M. De Michielis , G. Mazzeo , M. Fanciulli , R. Wacquez , M. Vinet , E. Prati

We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect and the conductance reaches the unitary-limit…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 W. G. van der Wiel , S. De Franceschi , T. Fujisawa , J. M. Elzerman , S. Tarucha , L. P. Kouwenhoven

Transport measurements at cryogenic temperatures through a few electron top gated quantum dot fabricated in a silicon/silicon-germanium heterostructure are reported. Variations in gate voltage induce a transition from an isolated dot toward…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Levente J. Klein , Donald E. Savage , Mark A. Eriksson

In a tunneling experiment across a quantum dot it is possible to change the coupling between the dot and the contacts at will, by properly tuning the trasparency of the barriers and the temperature. Gate voltages allow for changes of the…

Strongly Correlated Electrons · Physics 2009-11-10 Domenico Giuliano , Adele Naddeo , Arturo Tagliacozzo

Using different techniques, and Fermi-liquid relationships, we calculate the variation with applied magnetic field (up to second order) of the zero-temperature equilibrium conductance through a quantum dot described by the impurity Anderson…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 I. J. Hamad , C. Gazza , J. A. Andrade , A. A. Aligia , P. Roura-Bas , P. S. Cornaglia

We study the Kondo effect in a quantum dot coupled to half-metallic ferromagnetic electrodes in the regime of strong on-dot correlations. Using the equation of motion technique for nonequilibrium Green functions in the slave boson…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mariusz Krawiec

The interplay between the coupling of an interacting quantum dot to a conduction band and its connection to localized levels has been studied in a triple quantum dot arrangement. The electronic Dicke effect, resulting from quasi-resonant…

Mesoscale and Nanoscale Physics · Physics 2010-10-18 E. Vernek , P. A. Orellana , S. E. Ulloa

For the last decade, tunable quantum dot systems have allowed the investigation of Kondo physics wherein the quenching of a single spin on an artificial atom affects the conductance. The pseudogap Kondo model featuring a density of states…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 John Hopkinson , Karyn Le Hur , Emilie Dupont

We investigate the equilibrium and out-of-equilibrium Kondo effects in a single-level interacting quantum dot connected to two ferromagnetic leads. Within the non-crossing approximation, we calculate the total density of states (DOS), the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Bing Dong , H. L. Cui , S. Y. Liu , X. L. Lei

We report a strong Kondo effect (Kondo temperature ~ 4K) at high magnetic field in a selective area growth semiconductor quantum dot. The Kondo effect is ascribed to a singlet-triplet transition in the ground state of the dot. At the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 W. G. van der Wiel , S. De Franceschi , J. M. Elzerman , S. Tarucha , L. P. Kouwenhoven , J. Motohisa , F. Nakajima , T. Fukui

The Kondo effect in coupled quantum dots is investigated from the viewpoint of transmission spectroscopy using the slave-boson formalism of the Anderson model. The antiferromagnetic spin-spin coupling $J$ between the dots is taken into…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Tomosuke Aono , Mikio Eto

The Kondo effect in coupled quantum dots is investigated theoretically under magnetic fields. We show that the magnetoconductance (MC) illustrates peak structures of the Kondo resonant spectra. When the dot-dot tunneling coupling $V_C$ is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Tomosuke Aono , Mikio Eto

We investigate theoretically the linear conductance of a two-level quantum dot as a function of the gate voltage and different strength of coupling to the external electronic system (the reservoir). Apart from the weak coupling regime,…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. L. Chudnovskiy , S. E. Ulloa

We investigate a lateral semiconductor quantum dot with a large number of electrons in the limit of strong coupling to the leads. A Kondo effect is observed and can be tuned in a perpendicular magnetic field. This Kondo effect does not…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 C. Fuhner , U. F. Keyser , R. J. Haug , D. Reuter , A. D. Wieck

One-electron tunneling through a quantum dot with a strong magnetic field in the direction of the current is studied. The linear magneto-conductance is computed for a model parabolic dot with seven electrons in the intermediate states and…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Augusto Gonzalez , Roberto Capote

We demonstrate a tunable Kondo effect realized in small quantum dots. We can switch our dot from a Kondo impurity to a non-Kondo system as the number of electrons on the dot is changed from odd to even. We show that the Kondo temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Sara M. Cronenwett , Tjerk H. Oosterkamp , Leo P. Kouwenhoven

The Kondo effect emerges when a localized spin is screened by conduction electrons, giving rise to a strongly-correlated many-body ground state. In this work, we investigate this phenomenon in a GaAs/AlGaAs quantum dot, focusing on the…

Electronic states in silicon quantum dots are examined theoretically, taking into account a multivalley structure of the conduction band. We find that (i) exchange interaction hardly works between electrons in different valleys. In…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Yoko Hada , Mikio Eto
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