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Related papers: Zero-point spin-fluctuations of single adatoms

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In the presence of spin-orbit scattering, the splitting of an energy level in a generic small metal grain due to the Zeeman coupling to a magnetic field B depends on the direction of B, as a result of mesoscopic fluctuations. The anisotropy…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 P. W. Brouwer , X. Waintal , B. I. Halperin

We consider a reversal of the magnetic moment of a nano-magnet by the fluctuating spin-torque induced by a non-equilibrium current of electron spins. This is an example of the problem of the escape of a particle from a metastable state…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Yasuhiro Utsumi , Tomohiro Taniguchi

The magnetic properties of the weak itinerant ferromagnet ZrZn_2 are analyzed using Landau theory based on a comparison of density functional calculations and experimental data as a function of field and pressure. We find that the magnetic…

Materials Science · Physics 2009-11-10 I. I. Mazin , D. J. Singh

Spin fluctuations have a substantial influence on the electron and lattice behaviors in magnetic materials, which, however, is difficult to be tracked properly by prevalent first-principles methods. We propose a versatile self-adaptive…

Materials Science · Physics 2023-02-14 Zefeng Cai , Ke Wang , Yong Xu , Su-Huai Wei , Ben Xu

Thermal conductivity measurements have been performed on the superconducting ferromagnet UCoGe down to very low temperature and under magnetic field. In addition to the electronic quasiparticle thermal conductivity, additional contributions…

Strongly Correlated Electrons · Physics 2014-01-22 Mathieu Taupin , Ludovic Howald , Dai Aoki , Jacques Flouquet , Jean-Pascal Brison

We report the structural and magnetic properties of high-quality bulk single crystals of the kagome ferromagnet Fe$_3$Sn. The dependence of magnetisation on the magnitude and orientation of the external field reveals strong easy-plane type…

Zero resistance, diamagnetism (Meissner effect) and the energy gap in the excitation spectrum are the fundamental attributes of superconductivity. In nanoparticles with characteristic size 10 nm superconductivity is suppressed by the…

Superconductivity · Physics 2009-06-26 Terhi T. Hongisto , K. Yu. Arutyunov

Critical fluctuations play a fundamental role in determining the spin orders for low-dimensional quantum materials, especially for recently discovered two-dimensional (2D) magnets. Here we employ the quantum decoherence imaging technique…

Mesoscale and Nanoscale Physics · Physics 2024-07-02 Yuxin Li , Zhe Ding , Chen Wang , Haoyu Sun , Zhousheng Chen , Pengfei Wang , Ya Wang , Ming Gong , Hualing Zeng , Fazhan Shi , Jiangfeng Du

We measure the frequency spectra of random spin fluctuations, or "spin noise", in ensembles of (In,Ga)As/GaAs quantum dots (QDs) at low temperatures. We employ a spin noise spectrometer based on a sensitive optical Faraday rotation…

Mesoscale and Nanoscale Physics · Physics 2010-03-02 S. A. Crooker , J. Brandt , C. Sandfort , A. Greilich , D. R. Yakovlev , D. Reuter , A. D. Wieck , M. Bayer

We propose a phenomenological spin fluctuation theory for antiferromagnetic quantum tricritical point (QTCP), where the first-order phase transition changes into the continuous one at zero temperature. Under magnetic fields, ferromagnetic…

Strongly Correlated Electrons · Physics 2010-10-20 Takahiro Misawa , Youhei Yamaji , Masatoshi Imada

Recent advances in nanoscience have raised interest in the minimum bit size required for classical information storage, i.e. for bistability with suppressed quantum tunnelling and energy barriers that exceed ambient temperatures. In the…

Materials Science · Physics 2015-06-25 Tor O. Strandberg , Carlo. M. Canali , Allan H. MacDonald

We show that in magnetic nanostructures with a homogeneous magnetic order, the equilibrium spin current can be nonzero. For example, this is the case of a wide magnetic ring with the magnetization along the ring axis. The physical reason of…

Materials Science · Physics 2009-11-13 Vitalii K. Dugaev , Patrick Bruno

We present a theory of the magnetotransport in weakly disordered metals close to an antiferromagnetic quantum-critical point. The anisotropic scattering from critical spin fluctuations is strongly influenced by weak but isotropic scattering…

Strongly Correlated Electrons · Physics 2009-10-31 A. Rosch

We present a first-principles study of the surface magnetism induced by Cr, Mn, Fe and Co adatoms on the (111) surfaces of Rh, Pd, Ag, Ir, Pt and Au. We first describe how the different contributions to the surface magnetism enter the…

Mesoscale and Nanoscale Physics · Physics 2020-02-19 Sascha Brinker , Manuel dos Santos Dias , Samir Lounis

We illuminate the intriguing role played by spatial anisotropy in three-dimensional Luttinger semimetals featuring quadratic band touching and long-range Coulomb interactions. We observe the anisotropy to be subject to an exceptionally slow…

Strongly Correlated Electrons · Physics 2017-03-01 Igor Boettcher , Igor F. Herbut

The interplay between site dilution and quantum fluctuations in S=1 Heisenberg antiferromagnets on the square lattice is investigated using quantum Monte Carlo simulations. Quantum fluctuations are tuned by a single-ion anisotropy D. In the…

Strongly Correlated Electrons · Physics 2010-03-23 Tommaso Roscilde , Stephan Haas

Magnetic anisotropy plays an essential role in information technology applications of magnetic materials, providing a means to retain the long-term stability of a magnetic state in the presence of thermal fluctuations. Anisotropy consists…

Materials Science · Physics 2020-08-05 Richard F. L. Evans , Levente Rózsa , Sarah Jenkins , Unai Atxitia

Understanding the spin-relaxation mechanism of single adatoms is an essential step towards creating atomic magnetic memory bits or even qubits. Here we present an essentially parameter-free theory by combining \textit{ab-initio} electronic…

Mesoscale and Nanoscale Physics · Physics 2023-04-26 Haritz Garai-Marin , Manuel dos Santos Dias , Samir Lounis , Julen Ibañez-Azpiroz , Asier Eiguren

We theoretically and numerically investigate the spin fluctuations induced in a thermal atomic ensemble by an external fluctuating uniaxial magnetic field, in the context of a standard spin noise spectroscopy (SNS) experiment. We show that…

Quantum Physics · Physics 2023-10-05 J. Delpy , S. Liu , P. Neveu , C. Roussy , Th. Jolicoeur , F. Bretenaker , F. Goldfarb

We report on the synthesis of ferromagnetic cobalt nanocubes of various sizes using thermal pyrolysis method and the effect of shape anisotropy on the static and dynamic magnetic properties were studied. Shape anisotropy of approximately 10…

Materials Science · Physics 2010-03-10 D. Srikala , V. N. Singh , A. Banerjee , B. R. Mehta