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Related papers: Electronic exchange in quantum rings

200 papers

Microscopic theory of the nonradiative energy transfer in a system of III-V semiconductor quantum dots is elaborated in our work. The energy transfer both due to direct Coulomb and due to exchange interactions between two quantum dots…

Mesoscale and Nanoscale Physics · Physics 2017-11-22 O. P. Chikalova-Luzina , D. M. Samosvat , V. M. Vyatkin , G. G. Zegrya

The effect of orbital degrees of freedom on the exchange interactions in the spin-1 quasi-one-dimensional antiferromagnet CaV2O4 is systematically studied. For this purpose a realistic low-energy model with the parameters derived from the…

Materials Science · Physics 2015-06-23 Z. V. Pchelkina , I. V. Solovyev

Because of their long coherence times and potential for scalability, semiconductor quantum-dot spin qubits hold great promise for quantum information processing. However, maintaining high connectivity between quantum-dot spin qubits, which…

Mesoscale and Nanoscale Physics · Physics 2021-01-12 Haifeng Qiao , Yadav P. Kandel , Saeed Fallahi , Geoffrey C. Gardner , Michael J. Manfra , Xuedong Hu , John M. Nichol

Several prominent proposals have suggested that spins of localized electrons could serve as quantum computer qubits. The exchange interaction has been invoked as a means of implementing two qubit gates. In this paper, we analyze the…

Strongly Correlated Electrons · Physics 2016-08-31 Ari Mizel , Daniel A. Lidar

In [arXiv:2207.03377] the first closed formula of a faithful entanglement measure applicable to realistic electron systems has been derived. In the present work, we build on this key achievement with the ultimate goal of guiding the…

Quantum Physics · Physics 2023-12-12 Lexin Ding , Gesa Dünnweber , Christian Schilling

Density functionals with a range-separated treatment of the exchange energy are known to improve upon their semilocal forerunners and fixed-fraction hybrids. The conversion of a given semilocal functional into its short-range analog is not…

Chemical Physics · Physics 2019-09-09 Dimitri N. Laikov

The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock…

Nuclear Theory · Physics 2019-12-09 Tomoya Naito , Ryosuke Akashi , Gianluca Colò , Haozhao Liang , Xavier Roca-Maza

The spectral properties of up to four interacting electrons confined within a quasi one--dimensional system of finite length are determined by numerical diagonalization including the spin degree of freedom. The ground state energy is…

Condensed Matter · Physics 2009-10-22 Wolfgang Haeusler , Bernhard Kramer , PTB Braunschweig

In order to assess the accuracy of commonly used approximate exchange-correlation density functionals, we present a comparison of accurate exchange and correlation potentials, exchange energy densities and energy components with the…

Condensed Matter · Physics 2007-05-23 Claudia Filippi , Xavier Gonze , C. J. Umrigar

Commonly used semilocal density functional approximations for the exchange-correlation energy fail badly when the true two dimensional limit is approached. We show, using a quasi-two-dimensional uniform electron gas in the infinite barrier…

Materials Science · Physics 2015-05-13 Lucian A. Constantin

The Heisenberg exchange interaction between neighboring quantum dots allows precise voltage control over spin dynamics, due to the ability to precisely control the overlap of orbital wavefunctions by gate electrodes. This allows the study…

This paper derives and demonstrates a new, purely density-based ab initio approach for calculation of the energies and properties of many-electron systems. It is based upon the discovery of relationships that govern the "mechanics" of the…

Chemical Physics · Physics 2024-09-04 James C. Ellenbogen

We investigate quantum communication between the sites of a spin-ring with twisted boundary conditions. Such boundary conditions can be achieved by a flux through the ring. We find that a non-zero twist can improve communication through…

Quantum Physics · Physics 2009-11-10 S. Bose , B. -Q. Jin , V. E. Korepin

Theoretical approaches to one-dimensional and quasi-one-dimensional quantum rings with a few electrons are reviewed. Discrete Hubbard-type models and continuum models are shown to give similar results governed by the special features of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 S. Viefers , P. Koskinen , P. Singha Deo , M. Manninen

An exchange energy functional is proposed and tested for obtaining a class of excited-state energies using density-functional formalism. The functional is the excited-state counterpart of the local-density approximation functional for the…

Other Condensed Matter · Physics 2007-05-23 Prasanjit Samal , Manoj K. Harbola

We propose a scheme to implement the one-dimensional coined quantum walk with electrons transported through a two-dimensional network of spintronic semiconductor quantum rings. The coin degree of freedom is represented by the spin of the…

Mesoscale and Nanoscale Physics · Physics 2009-07-30 Orsolya Kálmán , Tamás Kiss , Péter Földi

A recently developed semiclassical approximation to exchange in one dimension is shown to be almost exact, with essentially no computational cost. The variational stability of this approximation is tested, and its far greater accuracy…

Chemical Physics · Physics 2014-08-20 Peter Elliott , Attila Cangi , Stefano Pittalis , E. K. U. Gross , Kieron Burke

We present a practical and accurate density functional for the exchange-correlation energy of electrons in two dimensions. The exchange part is based on a recent two-dimensional generalized-gradient approximation derived by considering the…

Strongly Correlated Electrons · Physics 2010-06-30 E. Rasanen , S. Pittalis , J. G. Vilhena , M. A. L. Marques

We model a spin-phase transition in a two-dimensional square array, or a lateral superlattice, of quantum rings in an external perpendicular homogeneous magnetic field. The electron system is placed in a circular cylindrical far-infrared…

The total energy of a quasi-one-dimensional electron system is calculated using density functional theory. It is shown that spontaneous ferromagnetic state in quantum wire occurs at low one-dimensional electron density. The critical…

Mesoscale and Nanoscale Physics · Physics 2013-01-14 A. A. Vasilchenko