English
Related papers

Related papers: Ferromagnetism in Quantum Dot Plaquettes

200 papers

We study numerically the ground state properties of the one-dimensional quarter-filled strongly correlated electronic system interacting antiferromagnetically with localized $S=1/2$ spins. It is shown that the charge-ordered state is…

Strongly Correlated Electrons · Physics 2009-11-11 Chisa Hotta , Masao Ogata , Hidetoshi Fukuyama

The t - J Hamiltonian of the spinful hard-core bosonic ring in the Nagaoka limit is solved. The energy spectrum becomes quantized due to presence of spin, where each energy level corresponds to a cyclic permutation state of the spin chains.…

Quantum Gases · Physics 2022-10-04 K. K. Kesharpu , E. A. Kochetov

We study the ground states and low-energy excitations of a generic Dirac material with spin-orbit coupling and a buckling structure in the presence of a perpendicular magnetic field. The ground states can be classified into three types…

Quantum Gases · Physics 2015-10-28 Wenchen Luo , Tapash Chakraborty

We report unexpected fluctuations in the positions of Coulomb blockade peaks at high magnetic fields in a small Si quantum dot. The fluctuations have a distinctive saw-tooth pattern: as a function of magnetic field, linear shifts of peak…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 L. P. Rokhinson , L. J. Guo , S. Y. Chou , D. C. Tsui

We study the properties of flat-bands that appear in a heterostructure composed of strands of different widths of graphene armchair nanoribbons. One of the flat-bands is reminiscent of the one that appears in pristine armchair nanoribbons…

Mesoscale and Nanoscale Physics · Physics 2022-02-18 P. A. Almeida , L. S. Sousa , Tome M. Schmidt , G. B. Martins

We propose an idea for probing spin states of two coupled quantum dots (CQD), by the dc Josephson current flowing through them. This theory requires weak coupling between CQD and electrodes, but allows arbitrary inter-dot tunnel coupling,…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu Zhu , Qing-feng Sun , Tsung-han Lin

A quantum theory of gravity is described in the case of a positive cosmological constant in 3+1 dimensions. Both old and new results are described, which support the case that loop quantum gravity provides a satisfactory quantum theory of…

High Energy Physics - Theory · Physics 2007-05-23 Lee Smolin

In order to understand the orbital and spin magnetization of a confined electronic system we analyze these ground state properties in the transition from a quantum dot to a quantum ring of finite thickness. The Coulomb interaction between…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gabriel Vasile , Vidar Gudmundsson , Andrei Manolescu

States of strongly interacting particles are of fundamental interest in physics, and can produce exotic emergent phenomena and topological structures. We consider here two-dimensional electrons in a magnetic field, and, departing from the…

Strongly Correlated Electrons · Physics 2022-03-16 Abhishek Anand , Jainendra K Jain , G J Sreejith

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

We investigate theoretically the transport properties of a closed Aharonov-Bohm interferometer containing two quantum dots in the strong coupling regime. We find two distinct physical scenarios depending on the strength of the interdot…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Rosa Lopez , David Sanchez , Minchul Lee , Mahn-Soo Choi , Pascal Simon , Karyn Le Hur

Inelastic light scattering measurements of low-lying collective excitations of electron double layers in the quantum Hall state at total filling nu_T=1 reveal a deep magnetoroton in the dispersion of charge-density excitations across the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Stefano Luin , Vittorio Pellegrini , Aron Pinczuk , Brian S. Dennis , Loren N. Pfeiffer , Ken W. West

We study a ferromagnetic instability in a doped single-band Hubbard model by means of dynamical mean-field theory with the continuous-time quantum Monte Carlo simulations. Examining the effect of the strong correlations in the system on the…

Strongly Correlated Electrons · Physics 2019-06-06 Yusuke Kamogawa , Joji Nasu , Akihisa Koga

We have investigated the electronic states of planar quantum dots at the ZnO interface containing a few interacting electrons in an externally applied magnetic field. In these systems, the electron-electron interaction effects are expected…

Mesoscale and Nanoscale Physics · Physics 2017-05-24 Tapash Chakraborty , Aram Manaselyan , Manuk Barseghyan

We investigate the transport properties of quantum dots placed in strong magnetic field using a quantum-mechanical ' approach based on the 2D tight-binding Hamiltonian with direct Coulomb interaction and the Landauer-B\"{u}ttiker (LB)…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 V. Moldoveanu , A. Aldea , A. Manolescu , M. Nita

The paper presents a computational study of the ground-state properties of a quantum nanomagnet possessing the shape of a finite two-legged ladder composed of 12 spins $S=1/2$. The system is described with isotropic quantum Heisenberg model…

Statistical Mechanics · Physics 2018-01-03 K. Szałowski , P. Kowalewska

A new theoretical method is introduced to study coherent electron transport in an interacting multilevel quantum dot. The method yields the correct behavior both in the limit of weak and strong coupling to the leads, giving a unified…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. Levy Yeyati , F. Flores , A. Martin-Rodero

Considerable evidence exists for the failure of the traditional theory of quantum critical points (QCPs), pointing to the need to incorporate novel excitations. The destruction of Kondo entanglement and the concomitant critical Kondo effect…

Strongly Correlated Electrons · Physics 2007-05-23 Stefan Kirchner , Lijun Zhu , Qimiao Si , D. Natelson

Using a fermionic renormalization group approach we analyse a model where the electrons diffusing on a quantum dot interact via Fermi-liquid interactions. Describing the single-particle states by Random Matrix Theory, we find that…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Ganpathy Murthy , Harsh Mathur

We construct a multi-band Hubbard model on the lattice obtained by "decorating" a closely packed $d$-dimensional lattice $\mathcal{M}$ (such as the triangular lattice) where $d\ge2$. We take the limits in which the Coulomb interaction and…

Strongly Correlated Electrons · Physics 2016-05-04 Akinori Tanaka , Hal Tasaki