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Related papers: Spin wave specific heat in quasiperiodic Fibonacci…

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Motivated by recent magnetic measurements on A3Cu3(PO4)4 (A=Ca,Sr) and Cu(3-Clpy)2(N3)2 (3-Clpy=3-Chloropyridine), both of which behave like one-dimensional ferrimagnets, we extensively investigate the ferrimagnetic specific heat with…

Strongly Correlated Electrons · Physics 2009-11-07 Takashi Nakanishi , Shoji Yamamoto

A modified spin-wave theory is applied to the one-dimensional quantum Heisenberg model with long-range ferromagnetic interactions. Low-temperature properties of this model are investigated. The susceptibility and the specific heat are…

Condensed Matter · Physics 2009-10-22 Hiroki Nakano , Minoru Takahashi

The low-energy structure and the thermodynamic properties of ferrimagnetic Heisenberg chains of alternating spins $S$ and $s$ are investigated by the use of numerical tools as well as the spin-wave theory. The elementary excitations are…

Statistical Mechanics · Physics 2009-10-31 Shoji Yamamoto , Takahiro Fukui , Toru Sakai

Modifying the conventional spin-wave theory in a novel manner based on the Wick decomposition, we present an elaborate thermodynamics of square-lattice quantum antiferromagnets. Our scheme is no longer accompanied by the notorious problem…

Strongly Correlated Electrons · Physics 2019-03-13 Shoji Yamamoto , Yusaku Noriki

Magnonic quasicrystals exceed the possibilities of spin wave (SW) manipulation offered by regular magnonic crystals, because of their more complex SW spectra with fractal characteristics. Here, we report the direct x-ray microscopic…

Recent experiments show that spin thermoelectrics is a promising approach to generate spin voltages. While spin chemical potentials are often limited to a surface layer of the order of the spin diffusion length, we show that…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Tamara S. Nunner , Felix von Oppen

We study the stroboscopic dynamics of a spin-$S$ object subjected to $\delta$-function kicking in the transverse magnetic field which is generated following the Fibonacci sequence. The corresponding classical Hamiltonian map is constructed…

Statistical Mechanics · Physics 2019-11-27 Sayak Ray , Subhasis Sinha , Diptiman Sen

We make a modified spin-wave description of the nuclear spin relaxation in Heisenberg alternating-spin chains with antiferromagnetic exchange coupling. In contrast with the conventional one-dimensional antiferromagnetic spin-wave theory,…

Statistical Mechanics · Physics 2009-10-31 Shoji Yamamoto

Theories based on the coupling between spin fluctuations and fermionic quasiparticles are among the leading contenders to explain the origin of high-temperature superconductivity, but estimates of the strength of this interaction differ…

We construct modified spin-wave thermodynamics for frustrated noncollinear antiferromagnets for the first time. The well-known modified spin-wave theory for collinear antiferromagnets diagonalizes a bosonic Hamiltonian subject to the…

Statistical Mechanics · Physics 2023-07-20 Shoji Yamamoto , Jun Ohara

We study the electronic energy spectra and wave functions on the square Fibonacci tiling, using an off-diagonal tight-binding model, in order to determine the exact nature of the transitions between different spectral behaviors, as well as…

Other Condensed Matter · Physics 2007-05-23 Shahar Even-Dar Mandel , Ron Lifshitz

A deformed fermion gas model aimed at taking into account thermal and electronic properties of quasiparticle systems is devised. The model is constructed by the fermionic Fibonacci oscillators whose spectrum is given by a generalized…

Statistical Mechanics · Physics 2017-05-18 Abdullah Algin , Ali Serdar Arikan

We study the low temperature thermodynamics of the quantum Heisenberg ferromagnet in three dimension for any value of the spin $ S \geq 1/2 $. We report on a rigorous proof of the validity of the spin-wave approximation for the excitation…

Mathematical Physics · Physics 2016-02-02 M. Correggi , A. Giuliani , R. Seiringer

The exact solution of the noncompact SL(2,C) Heisenberg spin magnet reveals a hidden symmetry of the energy spectrum. To understand its origin, we solve the spectral problem for the model within quasiclassical approach. In this approach,…

High Energy Physics - Theory · Physics 2014-11-18 S. E. Derkachov , G. P. Korchemsky , A. N. Manashov

We study quantum spin-1/2 Heisenberg ferromagnetic chains with dilute, random antiferromagnetic impurity bonds with modified spin-wave theory. By describing thermal excitations in the language of spin waves, we successfully observe a…

Disordered Systems and Neural Networks · Physics 2009-11-07 Xin Wan , Kun Yang , Chenggang Zhou , R. N. Bhatt

Ferromagnetic, in contrast to antiferromagnetic, Heisenberg chains can undergo a Spin-Peierls dimerization only at finite temperatures. They show reentrant behavior as a function of temperature, which might play a role for systems with…

Strongly Correlated Electrons · Physics 2011-10-19 A. Herzog , P. Horsch , A. M. Oles , J. Sirker

Spin waves are the fundamental excitations in magnetically ordered spin systems and are ubiquitously observed in magnetic materials. However, the standard understanding of spin waves as collective spin oscillations in an effective harmonic…

Strongly Correlated Electrons · Physics 2025-09-01 Anna Fancelli , Matías G. Gonzalez , Subhankar Khatua , Bella Lake , Michel J. P. Gingras , Jeffrey G. Rau , Johannes Reuther

The low-temperature free energy of the spin S quantum Heisenberg ferromagnetic chain in a strong magnetic field is obtained in a two-particle approximation by using exact solution of two-spin-wave problem. The result is beyond the…

Condensed Matter · Physics 2007-05-23 Michael Teitelman

We present a detailed study of the dynamics of electronic wavepackets in Fibonacci semiconductor superlattices, both in flat band conditions and subject to homogeneous electric fields perpendicular to the layers. Coherent propagation of…

Mesoscale and Nanoscale Physics · Physics 2009-10-28 Enrique Diez , Francisco Dominguez-Adame , Enrique Macia , Angel Sanchez

The electronic quasiparticle spectrum of a ferromagnetic film is investigated within the framework of the s-f model. Starting from the exact solvable case of a single electron in an otherwise empty conduction band being exchange coupled to…

Strongly Correlated Electrons · Physics 2009-10-31 R. Schiller , W. Nolting