Phase competition in frustrated anisotropic antiferromagnet in strong magnetic field
Journal of Magnetism and Magnetic Materials. 2021. Vol. 527. Article 167732.
O.I. Utesov, Syromyatnikov A. V.
We discuss theoretically a frustrated Heisenberg antiferromagnet in magnetic field close to the saturation one. It is demonstrated that a small biaxial anisotropy and/or the magnetic dipolar interaction produce a delicate balance between phases with a commensurate canted, incommensurate helical (conical), and fan spin orderings. As a result, different sequences of phase transitions are realized depending on values of these small anisotropic interactions. We derive analytical expressions for critical fields and ground-state energies of the phases which are in a quantitative agreement with our and previous Monte-Carlo simulations.
Research target: Physics
, , Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 No. 5 P. 054439
We discuss theoretically phase transitions in frustrated antiferromagnets with biaxial anisotropy or dipolar forces in magnetic field applied along the easy axis at T = 0. There are well-known sequences of phase transitions on the field increasing: the conventional spin-flop transition and the flop of the spiral plane at strong and weak easy-axis anisotropy, respectively. We argue that ...
Added: January 16, 2021
, , Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 98 No. 18 P. 184406
We discuss theoretically frustrated Heisenberg spiral magnets in magnetic field H. We demonstrate that small anisotropic spin interactions (single-ion biaxial anisotropy or dipolar forces) select the plane in which spins rotate (spiral plane) and can lead to the spiral plane flop upon in-plane field increasing. Expressions for the critical fields Hflop are derived. It is shown that measuring ...
Added: January 16, 2021
, , Journal of Magnetism and Magnetic Materials 2019 Vol. 475 P. 98-102
We provide a theoretical description of frustrated multiferroic MnI2 with a spiral magnetic ordering in magnetic field h. We demonstrate that subtle interplay of exchange coupling, dipolar forces, hexagonal anisotropy, and the Zeeman energy account for the main experimental findings observed recently in this material (Kurumaji et al., Phys. Rev. Lett. 106 (2011) 167206). We ...
Added: January 16, 2021
Transition from spiral to ferromagnetic structure in Fe1−xCoxSi compounds: Small-angle neutron scattering study
, , et al., Annals of Physics 2022 Vol. 447 Article 169132
The cubic noncentrosymmetric structure of the B20 compounds produces the spin helix with the wave vector ks = D/J balanced by the competition of two interactions: the large ferromagnetic exchange interaction J and small antisymmetric Dzyaloshinskii–Moriya (DM) interaction D. The mixed Fe1−xCoxSi compounds demonstrate a switch of the sign of magnetic chirality in dependence of ...
Added: March 6, 2023
, , et al., Crystals 2018 Vol. 8 No. 246 P. 1-26
Ground-state properties of bosons interacting via inverse square potential (three dimensional Calogero-Sutherland model) are analyzed. A number of quantities scale with the density and can be naturally expressed in units of the Fermi energy and Fermi momentum multiplied by a dimensionless constant (Bertsch parameter). Two analytical approaches are developed: the Bogoliubov theory for weak and ...
Added: October 22, 2018
, Special Purpose Computers for Statistical Physics: achievements and lessons / Cornell University. Series arXiv "math". 2021. No. 2107.02406.
In the late 80s and 90s, theoretical physicists of the Landau Institute for Theoretical Physics designed and developed several specialized computers for challenging computational problems in the physics of phase transitions. These computers did not have a central processing unit. They optimize algorithms to handle elementary operations on integers - read, write, compare, and count. The approach allowed them to achieve recording ...
Added: July 26, 2021
, , , Chemical Communications 2021 Vol. 57 P. 3983-3986
We develop a new quantitative molecular theory of liquid-phase dipolar polymer gels. We model monomer units of the polymer network as a couple of charged sites separated by a fluctuating distance. For the first time, within the random phase approximation, we have obtained an analytical expression for the electrostatic free energy of the dipolar gel. ...
Added: March 26, 2021
, , et al., Estimating the Density of States of Frustrated Spin Systems / Cornell University. Series cond-mat "arxiv.org". 2018. No. 1808.04340.
Estimating the density of states of systems with rugged free energy landscapes is a notoriously difficult task of the utmost importance in many areas of physics ranging from spin glasses to biopolymers to quantum computing. Some of the standard approaches suffer from a spurious convergence of the estimates to metastable minima, and these cases are ...
Added: October 17, 2018
, , Успехи физических наук 2018 Т. 188 № 11 С. 1199-1202
Conditions for applicability of mean field theory to the thermodynamics of the 4He crystal surface are determined. Although the faceting transition itself is of Berezinsky—Kosterlitz—Thouless type, the thermodynamic potential outside a narrow neighborhood of the transition temperature can be expanded in the spirit of the Landau theory of second-order phase transitions. The Ginzburg—Levanyuk parameter is estimated. ...
Added: November 13, 2018
Critical fluctuations beyond the quantum phase transition in Dzyaloshinskii-Moriya helimagnets Mn_(1-x)Fe_xSi
, , et al., Journal of Experimental and Theoretical Physics 2021 Vol. 132 No. 4 P. 588-595
Polarized small-angle neutron scattering was used for studying of critical fluctuations in the Dzyaloshinskii–Moriya helimagnets Mn_(1 – x)Fe_xSi with x = 0.10, 0.15, 0.20. The Mn_(1 – x)Fe_xSi compounds are helically ordered below Tc and show a helical fluctuation regime above Tc in a wide range up to TDM. The critical temperatures Tc and TDM decrease with ...
Added: May 31, 2021
, , Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 99 No. 13 P. 134412
We theoretically address the problem of cubic B20 helimagnets with a small concentration c <<1 of defect bonds in external magnetic field H, which is relevant to mixed B20 compounds at small dopant concentrations. We assume that the Dzyaloshinskii-Moriya interaction and the exchange coupling constant are changed on imperfect bonds which leads to distortion of the conical spiral ...
Added: January 16, 2021
, , Journal of Physics: Conference Series 2021 Vol. 1740 P. 1-5
We formulate the problem of the universality class investigation using machine learning. We chose an example of the universality class of the two-dimensional 4-state Potts model. There are four known models within the universality class – the 4-state Potts model, the Baxter-Wu model, the Ashkin-Teller model, and the Turban model. All four of them together ...
Added: February 19, 2021
, Physical Review B: Condensed Matter and Materials Physics 2022 Vol. 105 Article 054435
A simple mean-field description of frustrated antiferromagnets on hexagonal lattices, aimed to describe the high-temperature part of the temperature-magnetic field phase diagram, is proposed. It is shown that an interplay between modulation vector symmetry, Zeeman energy, and magnetodipolar interaction leads to stabilization of the triple-Q skyrmion lattice in a certain region of the phase diagram. The corresponding analytical ...
Added: March 2, 2022
, , et al., Поверхность. Рентгеновские, синхротронные и нейтронные исследования 2021 № 11 С. 28-33
The structural features and valence states of Fe in substituted strontium ferrite Sr2LaFe3O9–δ after a series of annealing events in vacuum at different temperatures from 400°C to 650°C are studied by X-ray diffraction (XRD) and Mssbauer spectroscopy. According to X-ray data, the two samples with extreme (in terms of oxygen content) compositions (Sr2LaFe3О9 and Sr2LaFe3О8) are single phase ...
Added: October 26, 2022
Spin wave stiffness and damping in a frustrated chiral helimagnet Co8Zn8Mn4 as measured by small-angle neutron scattering
, , et al., Physical Review Research 2022 Vol. 4 No. 2 Article 023239
Multiple intriguing low-temperature phenomena have recently been discovered in the family of chiral cubic Co-Zn-Mn compounds with a β-Mn-type structure. In particular, Co8Zn8Mn4 displays a reduction of the helical spiral pitch on cooling along with lattice shape transformations of metastable skyrmions and the manifestation of peculiar magnetic textures due to strong magnetocrystalline anisotropy. Here we report on temperature-dependent measurements ...
Added: September 27, 2022
Thermodynamically stable skyrmion lattice in a tetragonal frustrated antiferromagnet with dipolar interaction
, Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 103 No. 6 Article 064414
Motivated by recent experimental results for GdRu2Si2 [Khanh et al., Nat. Nanotechnol. 15, 444 (2020)], in which a nanometric square skyrmion lattice was observed, we propose a simple analytical mean-field description of the high-temperature part of the phase diagram of centrosymmetric tetragonal frustrated antiferromagnets with dipolar interaction in the external magnetic field. Dipolar forces provide ...
Added: February 9, 2021
, , et al., Scientific Reports 2021 Vol. 11 Article 24054
We demonstrate a new type of non-Hermitian phase transition in open systems far from thermal equilibrium, which can have place in the absence of an exceptional point. This transition takes place in coupled systems interacting with reservoirs at different temperatures. We show that the spectrum of energy flow through the system caused by the temperature ...
Added: January 2, 2022
, Доклады Академии наук 2011 Т. 436 № 3 С. 295-298
In a recent paper we proposed a new model of the dynamics of locally interacting particles (with a mean-field type interaction) and proved that in the limit of weak interactions finite systems of particles (or CML) may demonstrate both the synchronization, and independent behavior (i.e. the phase transition takes place), depending on fine properties of the interaction. Fundamental technical limitation there ...
Added: November 26, 2014
Signature of anisotropic exchange interaction revealed by vector-field control of the helical order in FeGe thin plate
, , et al., Physical Review Research 2021 Vol. 3 No. 1 Article 013094
We investigated the low-temperature helical magnetic structures in a thin plate of chiral magnet FeGe, paying special attention to the variation of the magnetic modulation period with the angle of an applied magnetic field. A unique vector-field setup allowed us to continuously rotate the helical texture in the sample plane while measuring high-resolution resonant small-angle ...
Added: January 31, 2021
Molecular dynamics analysis of elastic properties and new phase formation during amorphous ices transformations
, , Scientific Reports 2022 Vol. 12 No. 1 Article 13325
Unlike conventional first-order phase transitions, the kinetics of amorphous-amorphous transitions has been much less studied. The ultrasonic experiments on the transformations between low-density and high-density amorphous ice induced by pressure or heating provided the pressure and temperature dependencies of elastic moduli. In this article, we make an attempt to build a microscopic picture of these ...
Added: August 8, 2022
, , ChemPhysChem 2023 Vol. 24 No. 6 Article e202200730
The transition of warm dense fluid hydrogen from an insulator to a conducting state at pressures of about 20–400 GPa and temperatures of 500–5000 K has been the subject of active scientific research over the past few decades. However, various experimental and theoretical methods do not provide consistent results. In this work, we have applied the restricted ...
Added: January 31, 2023
Nonlocal density functional theory of water taking into account many-body dipole correlations: Binodal and surface tension of 'liquid-vapour' interface
, , Journal of Physics: Condensed Matter 2020 Vol. 32 No. 36 Article 365001
In this paper we formulate a nonlocal density functional theory of inhomogeneous water. We model a water molecule as a couple of oppositely charged sites. The negatively charged sites interact with each other through the Lennard-Jones potential (steric and dispersion interactions), square-well potential (short-range specific interactions due to electron charge transfer), and Coulomb potential, whereas ...
Added: April 9, 2020
, , et al., Physical Review A: Atomic, Molecular, and Optical physics 2019 Vol. 99 No. 6 Article 063821
The analysis of single-mode photon fluctuations and their counting statistics at the superradiant phase transition is presented. The study concerns the equilibrium Dicke model in a regime where the Rabi frequency, related to a coupling of the photon mode with a finite-number qubit environment, plays the role of the transition's control parameter. We use the ...
Added: October 29, 2021
, , et al., Успехи физических наук 2016 Т. 186 № 9 С. 628-632
Показано, что магнитная фазовая T — x-диаграмма твёрдых растворов замещения Mn1-xFexSi характеризуется наличием двух квантовых критических точек, первая из которых, x* ~ 0,11, соответствует исчезновению дальнего спирального магнитного порядка, а вторая, xc ~ 0,24, — подавлению магнитной фазы с ближним магнитным порядком. Установлено, что микроскопической причиной возникновения сложного квантового критического режима является эволюция структуры поверхности Ферми, обусловленная изменением состава ...
Added: October 2, 2016