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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

In this work, we explore the magnetic behavior of diluted spin-ice systems, where magnetic moments are randomly removed at various concentrations. We concentrate on features in which the effect of long range dipolar interactions (usually…

Statistical Mechanics · Physics 2024-11-08 M. Gorsd , S. A. Grigera , R. A. Borzi

The orbital degrees of freedom are of vital importance in explanation of various phenomena. Among them is the orbital-selective Mott transition (OSMT), which is thought to occur in several materials as Ca$_{2-x}$Sr$_x$RuO$_4$ and…

Strongly Correlated Electrons · Physics 2015-11-24 E Plekhanov , A Avella , F Mancini , F P Mancini

A detailed study of the low-temperature physics of an interacting double quantum dot system in a T-shape configuration is presented. Each quantum dot is modeled by a single Anderson impurity and we include an inter-dot electron-electron…

Mesoscale and Nanoscale Physics · Physics 2013-03-05 Irisnei L. Ferreira , P. A. Orellana , G. B. Martins , F. M. Souza , E. Vernek

We discuss the physics of a of a spin-1 quantum dot, coupled to two metallic leads and develop a simple model for the temperature dependence of its conductance. Such quantum dots are described by a two-channel Kondo model with asymmetric…

Strongly Correlated Electrons · Physics 2007-08-15 Anna Posazhennikova , Babak Bayani , P. Coleman

The Mott transition in a multi-orbital Hubbard model involving subbands of different widths is studied within the dynamical mean field theory. Using the iterated perturbation theory for the quantum impurity problem it is shown that at low…

Strongly Correlated Electrons · Physics 2009-11-10 A. Liebsch

The influence of configurational disorder on the magnetic properties of diluted Heisenberg spin systems is studied with regard to the ferromagnetic stability of diluted magnetic semiconductors. The equation of motion of the magnon Green's…

Disordered Systems and Neural Networks · Physics 2015-06-25 Guixin Tang , Wolfgang Nolting

Dissipation is ubiquitous in nature and plays a crucial role in quantum systems such as causing decoherence of quantum states. Recently, much attention has been paid to an intriguing possibility of dissipation as an efficient tool for…

Quantum Gases · Physics 2017-12-29 Takafumi Tomita , Shuta Nakajima , Ippei Danshita , Yosuke Takasu , Yoshiro Takahashi

Dilution effects on spin-1/2 quantum Heisenberg antiferromagnets with a non-magnetic spin-gapped ground state are studied by means of the qunatum Monte Carlo simulation. In the site-diluted system, an antiferromagnetic long-range order…

Disordered Systems and Neural Networks · Physics 2009-11-07 Chitoshi Yasuda , Synge Todo , Munehisa Matsumoto , Hajime Takayama

We study quantum corrections to conductivity in a 2D system with a smooth random potential and strong spin-orbit splitting of the spectrum. We show that the interference correction is positive and down to the very low temperature can exceed…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander P. Dmitriev , Igor V. Gornyi , Valentin Yu. Kachorovskii

The coherent spin dependent transport through a set of two capacitively coupled quantum dots placed in a magnetic field is considered within the equation of motion method. The magnetic field breaks the spin degeneracy. For special choices…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. Lipinski , D. Krychowski

The effect of an in-plane magnetic field upon open quasi-two-dimensional electron and hole systems is investigated in terms of the carrier ground-state spectrum. The magnetic field, classified as weak from the viewpoint of correlation…

Disordered Systems and Neural Networks · Physics 2009-11-10 Yu. V. Tarasov

We study by dynamical mean field theory the ground state of a quarter-filled Hubbard model of two bands with different bandwidths. At half-filling, this model is known to display an orbital selective Mott transition, with the narrower band…

Strongly Correlated Electrons · Physics 2018-07-11 Francesco Grandi , Adriano Amaricci , Massimo Capone , Michele Fabrizio

The transport properties of a double quantum-dot device with one of the dots coupled to perfect conductors are analyzed using the numerical renormalization group technique and slave-boson mean-field theory. The coupling between the dots…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. S. Cornaglia , D. R. Grempel

To understand the interplay between nematic fluctuation and superconductivity in iron-based superconductors, we performed a systematic study of the realistic two-orbital Hubbard model by using the constrained-path quantum Monte Carlo…

Strongly Correlated Electrons · Physics 2018-11-14 Guangkun Liu , Shichao Fang , Xiaojun Zheng , Zhongbing Huang , Haiqing Lin

We consider spin and orbital Kondo effect in a parallel arrangement of two strongly electrostatically coupled quantum dots. Increasing the exchange of electrons between the dots through the attached leads induces a smooth crossover between…

Mesoscale and Nanoscale Physics · Physics 2007-10-24 A. L. Chudnovskiy , Frank Hellmuth , V. Kagalovsky

We investigate the Kondo effect in a double-quantum-dot which is capacitively coupled to a charge-Qubit. It is shown that due to this capacitive coupling, the bare inter-dot repulsive interaction in the double-quantum-dot is effectively…

Strongly Correlated Electrons · Physics 2018-06-20 S. Mojtaba Tabatabaei

We calculate the finite temperature and non-equilibrium electric current through systems described generically at low energy by a singlet and \emph{two} spin doublets for $N$ and $N \pm 1$ electrons respectively, coupled asymmetrically to…

Strongly Correlated Electrons · Physics 2011-08-24 P. Roura-Bas , L. Tosi , A. A. Aligia , K. Hallberg

The two-orbital degenerate Hubbard model with distinct hopping integrals is studied by combining dynamical mean-field theory with quantum Monte Carlo simulations. The role of orbital fluctuations for the nature of the Mott transition is…

Strongly Correlated Electrons · Physics 2009-11-11 Akihisa Koga , Norio Kawakami , T. M. Rice , Manfred Sigrist

The dissipaton equations of motion (DEOM) method is one of the most popular methods for simulating quantum impurity systems. In this article, we use DOEM theory to deal with the Kondo problem of the double quantum dots (DQDs) impurity…

Quantum Physics · Physics 2023-05-30 Zi-Hao Chen , YiJing Yan