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Related papers: Valley Kondo Effect in Silicon Quantum Dots

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We analyze the optically induced Kondo effect in the absorption spectrum for a quantum dot with an even number of electrons, for which the Kondo effect does not occur in the ground state. The Kondo exchange couplings generated for…

Condensed Matter · Physics 2007-05-23 T. Fujii , A. Furusaki , N. Kawakami , M. Sigrist

We have measured the Kondo effect in a quantum ring connected to three terminals. In this configuration non-linear transport measurements allow to check which lead contributes to the Kondo density of states (DOS) and which does not. When…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 R. Leturcq , L. Schmid , K. Ensslin , Y. Meir , D. C. Driscoll , A. C. Gossard

We systematically study the influence of ferromagnetic leads on the Kondo resonance in a quantum dot tuned to the local moment regime. We employ Wilson's numerical renormalization group method, extended to handle leads with a spin…

Mesoscale and Nanoscale Physics · Physics 2011-11-10 M. Sindel , L. Borda , J. Martinek , R. Bulla , J. Koenig , G. Schoen , S. Maekawa , J. von Delft

We present lateral transport measurements on strongly, vertically coupled quantum dots formed in separate quantum wells in a GaAs/AlGaAs heterostructure. Coulomb oscillations are observed forming a honeycomb lattice consistent with two…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 A. W. Rushforth , C. G. Smith , I. Farrer , D. A. Ritchie , G. A. C. Jones , D. Anderson , M. Pepper

Spin qubits hosted in silicon (Si) quantum dots (QD) are attractive due to their exceptionally long coherence times and compatibility with the silicon transistor platform. To achieve electrical control of spins for qubit scalability, recent…

The ability to control electronic states at the nanoscale has contributed to our modern understanding of condensed matter. In particular, quantum dot circuits represent model systems for the study of strong electronic correlations,…

Mesoscale and Nanoscale Physics · Physics 2018-07-25 M. M. Desjardins , J. J. Viennot , M. C Dartiailh , L. E. Bruhat , M. R. Delbecq , M. Lee , M. -S. Choi , A. Cottet , T. Kontos

Quantum dots in silicon are promising candidates for implementation of solid-state quantum information processing. It is important to understand the effects of the multiple conduction band valleys of silicon on the properties of these…

Mesoscale and Nanoscale Physics · Physics 2013-08-27 John King Gamble , M. A. Eriksson , S. N. Coppersmith , Mark Friesen

The effect of a magnetic field on the spectral density of a $\rm{S=1/2}$ Kondo impurity is investigated at zero and finite temperatures by using Wilson's numerical renormalization group method. A splitting of the total spectral density is…

Strongly Correlated Electrons · Physics 2009-10-31 T. A. Costi

Research on Si quantum dot spin qubits is motivated by the long spin coherence times measured in Si, yet the orbital spectrum of Si dots is increased as a result of the valley degree of freedom. The valley degeneracy may be lifted by the…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Dimitrie Culcer , Lukasz Cywinski , Qiuzi Li , Xuedong Hu , S. Das Sarma

We study the Kondo effect of a two-orbital vertical quantum dot (QD) coupled to two ferromagnetic leads by employing an equation of motion method. When the ferromagnetic leads are coupled with parallel spin polarization, we find three peaks…

Strongly Correlated Electrons · Physics 2011-04-19 Hitoshi Yoshizumi , Kensuke Inaba , Tomoko Kita , Sei-ichiro Suga

Electrons confined in Si quantum dots possess orbital, spin, and valley degrees of freedom (d.o.f.). We perform Landau-Zener-Stuckelberg-Majorana (LZSM) interferometry on a Si double quantum dot that is strongly coupled to a microwave…

Mesoscale and Nanoscale Physics · Physics 2018-10-17 X. Mi , S. Kohler , J. R. Petta

The current noise in a quantum dot coupled to two leads is investigated in the Kondo regime with and without the influence of magnetic fields by employing a finite-$U$ slave-boson mean field theory to calculate the current-current…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Bing Dong , X. L. Lei

We consider a quantum dot coupled to two BCS superconductors with same gap energies $\Delta$. The transport properties are investigated by means of infinite-$U$ noncrossing approximation. In equilibrium density of states, Kondo effect shows…

Superconductivity · Physics 2016-08-31 S. Y. Liu , X. L. Lei

We study the Kondo effect in the electron transport through a quantum dot coupled to ferromagnetic leads, using a real-time diagrammatic technique which provides a systematic description of the nonequilibrium dynamics of a system with…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yasuhiro Utsumi , Jan Martinek , Gerd Schön , Hiroshi Imamura , Sadamichi Maekawa

Electron tunneling through quantum-dots side coupled to a quantum wire, in equilibrium and nonequilibrium Kondo regime, is studied. The mean-field finite-$U$ slave-boson formalism is used to obtain the solution of the problem. We have found…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Pedro A. Orellana , Gustavo A. Lara , Enrique V. Anda

Motivated by recent experiments, in which the Kondo effect has been observed for the first time in a double quantum-dot structure, we study electron transport through a system consisting of two ultrasmall, capacitively-coupled dots with…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Teemu Pohjola , Herbert Schoeller , Gerd Schön

We investigate the influence of an electromagnetic environment, characterized by a finite impedance $Z(\omega)$, on the Kondo effect in quantum dots. The circuit voltage fluctuations couple to charge fluctuations in the dot and influence…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Serge Florens , Pascal Simon , Sabine Andergassen , Denis Feinberg

We investigate the dynamical and transport features of a Kondo dot side-coupled to a topological superconductor (TS). The Majorana fermion states (MFS) formed at the ends of the TS are found to be able to alter the Kondo physics profoundly:…

Strongly Correlated Electrons · Physics 2012-10-24 Minchul Lee , Jong Soo Lim , Heunghwan Khim , Rosa Lopez

We present measurements on the Kondo-effect in a small quantum dot connected strongly to one lead and weakly to the other. The conductance of the dot reveals an offset of the Kondo resonance at zero magnetic field. While the resonance…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 F. Simmel , R. H. Blick , J. P. Kotthaus , W. Wegscheider , M. Bichler

Exchange interaction within a quantum dot strongly affects the transport through it in the Kondo regime. In a striking difference with the results of the conventional model, where this interaction is neglected, here the temperature and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Pustilnik , L. I. Glazman