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Related papers: Graphene-based quantum heterospin graphs

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In the quest for high-spin building blocks to form covalently bonded 1D or 2D materials with controlled magnetic interactions, $\pi$-electron magnetism provides an ideal framework to engineer large ferromagnetic interactions between…

Mesoscale and Nanoscale Physics · Physics 2024-07-02 Elia Turco , Fupeng Wu , Gonçalo Catarina , Nils Krane , Ji Ma , Roman Fasel , Xinliang Feng , Pascal Ruffieux

The emergence of spinon quasiparticles, which carry spin but lack charge, is a hallmark of collective quantum phenomena in low-dimensional quantum spin systems. While the existence of spinons has been demonstrated through scattering…

The dynamical behaviour of the quantum state of different quantum spin chains, with designed site dependent interaction strengths, is analyzed when the initial state belongs to the one excitation subspace. It is shown that the inhomogeneous…

Quantum Physics · Physics 2022-10-26 Alejandro Ferrón , Pablo Serra , Omar Osenda

Spin dependent electron transport measurements on graphene are of high importance to explore possible spintronic applications. Up to date all spin transport experiments on graphene were done in a semi-classical regime, disregarding quantum…

Mesoscale and Nanoscale Physics · Physics 2014-05-01 M. H. D. Guimaraes , P. J. Zomer , I. J. Vera-Marun , B. J. van Wees

We perform extensive first-principles calculations for heterostructures composed of monolayer graphene and hexagonal boron nitride (hBN). Employing a symmetry-derived minimal tight-binding model, we extract orbital and spin-orbit coupling…

Mesoscale and Nanoscale Physics · Physics 2019-03-29 Klaus Zollner , Martin Gmitra , Jaroslav Fabian

We investigate spin-$\frac{1}{2}$ anisotropic model of a linear chain of triangles with competing ferro- and antiferromagnetic interactions and ferromagneic Heisenberg interactions between triangles. For a certain ratio between interactions…

Strongly Correlated Electrons · Physics 2023-08-11 V. Ya. Krivnov , D. V. Dmitriev

The spin-1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain with ferromagnetic next-nearest-neighbour (NNN) interaction is investigated. The ground state is the Haldane phase for weak NNN interaction, and is the ferromagnetic…

Strongly Correlated Electrons · Physics 2013-05-10 Kazuo Hida , Ken'ichi Takano , Hidenori Suzuki

Graphene nanostructures can be engineered with atomic precision to display customized electronic states with application in spintronics or quantum technologies. In order to take advantage of their full potential, their charge and spin state…

As a nuclear spin model of scalable quantum register, the one-dimensional chain of the magnetic atoms with nuclear spins 1/2 substituting the basic atoms in the plate of nuclear spin free easy-axis 3D antiferromagnet is considered. It is…

Quantum Physics · Physics 2008-12-02 A. A. Kokin , V. A. Kokin

Monolayer graphene with an energy gap presents a pseudospin symmetry broken ferromagnet with a perpendicular pseudomagnetization whose direction is switched by altering the type of doping between n and p. We demonstrate an electrical…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Leyla Majidi , Malek Zareyan

We consider the statics and dynamics of distinguishable spin-1/2 systems on an arbitrary graph G with N vertices. In particular, we consider systems of quantum spins evolving according to one of two hamiltonians: (i) the XY hamiltonian…

Quantum Physics · Physics 2007-05-23 Tobias J. Osborne

Predictions state that graphene can spontaneously develop magnetism from the Coulomb repulsion of its $\pi$-electrons, but its experimental verification has been a challenge. Here, we report on the observation and manipulation of individual…

Mesoscale and Nanoscale Physics · Physics 2019-01-15 Jingcheng Li , Sofia Sanz , Martina Corso , Deung Jang Choi , Diego Peña , Thomas Frederiksen , Jose Ignacio Pascual

Electronic band structures in hydrogenated graphene are theoretically investigated by means of first-principle calculations and an effective tight-binding model. It is shown that regularly designed hydrogenation to graphene gives rise to a…

Mesoscale and Nanoscale Physics · Physics 2024-08-05 Yong-Cheng Jiang , Toshikaze Kariyado , Xiao Hu

In moir\'e graphene systems, electronic interactions lift spin and valley degeneracies, leading to symmetry-broken ground states. In helical trilayer graphene (HTG), we uncover a distinct interaction-driven mechanism in which the roles of…

Quantum spin rings represent fundamental model systems that exhibit distinctive quantum phenomena-such as quantum critical behavior and quasiparticle excitations-arising from their periodic boundary conditions and enhanced quantum…

Several experiments have recently found room-temperature ferromagnetism in graphite-like carbon based materials. This paper offers a model explaining such ferromagnetism by using an asymmetric nano-graphene. Our first typical model is…

Mesoscale and Nanoscale Physics · Physics 2011-01-28 Norio Ota , Narjes Gorjizadeh , Yoshiyuki Kawazoe

Using the density matrix renormalization group technique, we evaluate the low-energy spectrum (ground state and first excited states) of the anisotropic antiferromagnetic spin-one-half chain under magnetic fields. We study both homogeneous…

Strongly Correlated Electrons · Physics 2009-11-07 F. Capraro , C. Gros

We investigate the ground-state properties of triangular graphene nanoflakes with zigzag edge configurations. The description of zero-dimensional nanostructures requires accurate many-body techniques since the widely used density-functional…

Strongly Correlated Electrons · Physics 2018-01-24 I. Hagymasi , O. Legeza

In this work, the spin wave calculations were carried out using the Heisenberg Hamiltonian to study the allowed spin waves of zigzag and armchair edged stripes for ferromagnetic nanodots arrayed in a 2D honeycomb lattice \cite{Selim2011}.…

Mesoscale and Nanoscale Physics · Physics 2011-10-27 Maher Ahmed

We study the magnetic properties of nanometer-sized graphene structures with triangular and hexagonal shapes terminated by zig-zag edges. We discuss how the shape of the island, the imbalance in the number of atoms belonging to the two…

Mesoscale and Nanoscale Physics · Physics 2007-10-30 J. Fernandez-Rossier , J. J. Palacios