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1.
Influence of Dzyaloshinskii-Moriya interaction on the magnetic vortex reversal in an off-centered nanocontact geometry 下载免费PDF全文
Hua-Nan Li 《中国物理 B》2022,31(9):97501-097501
The influence of Dzyaloshinskii-Moriya interaction (DMI) on the vortex reversal driven by an out-of-plane spin-polarized current in an off-centered nanocontact structure is investigated. The simulation results show that DMI plays a vital role in vortex core reversal, including reversal current density, reversal velocity and reversal time. Under the influence of DMI, magnetic vortices still reverse polarity through the nucleation and annihilation of vortex and anti-vortex, with some peculiar characteristics. These results open up new possibilities for the application of magnetic vortex-based spin-transfer encryption nano-storage. 相似文献
2.
主要研究了具有交错Dzyaloshinskii-Moriya(DM)相互作用的反铁磁Heisenberg链的纠缠.基于 density-matrix renormalization group(DMRG)的数值计算表明,交错DM相互作用消除了系统在外磁场H=2处的二级量子相变,从而量子纠缠反常行为也随之消失;同时纠缠范围的发散也被消除,意味着该模型因子化点的消失.交错DM相互作用导致系统在任意强场下也不会达到铁磁饱和状态,从而保持着自旋纠缠.交错DM相互作用有利于通过外场调控纠缠程度和纠缠范
关键词:
Dzyaloshinskii-Moriya相互作用
量子纠缠
量子相变
纠缠范围 相似文献
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4.
《Surface Science Reports》2023,78(3):100605
Recently there has been an explosion of research related to the Dzyaloshinskii-Moriya interaction (DMI) in magnetic and multiferroic materials. This article reviews the key themes in this research and provides insight into the consequences of the DMI through simple theoretical models. The topics covered include new magnetic structures such as skyrmions and changes in domain wall structures along with their motion under a variety of driving fields. In addition, the influence of DMI on linear and nonlinear spin wave behavior is discussed. Multiferroic materials and new two-dimensional materials with DMI are briefly discussed. Finally, we also present an overview of different DMI materials and their characteristic parameters and potential applications. 相似文献
5.
Dzyaloshinskii-Moriya interaction(DMI) is the key ingredient of chiral spintronic phenomena and the emerging technologies based on such phenomena. A nonzero DMI usually occurs at magnetic interfaces or within non-centrosymmetric single crystals.Here, we report the observation of a strong unexpected DMI within a centrosymmetric polycrystalline ferromagnet that has neither a crystal inversion symmetry breaking nor a composition gradient. This DMI is a bulk effect, increases with the thickness of t... 相似文献
6.
Alekseev PA Mignot JM Nemkovski KS Rybina AV Lazukov VN Ivanov AS Iga F Takabatake T 《J Phys Condens Matter》2012,24(20):205601
Peculiarities in the lattice dynamics of the Kondo insulator Y bB(12) have been studied by inelastic neutron scattering. Selected phonon modes were traced above and below the temperature region (T ~ 50 K) where the gap opens in the electron density of states. The intensities of some low-energy modes exhibit an anomalous temperature dependence for q vectors close to the Brillouin zone boundary, suggesting a renormalization of the phonon eigenvectors. This effect is thought to arise from a coupling with magnetic excitations of the same symmetry, which exist at nearby energies. It is argued that this magnetovibrational coupling may in turn play a role in the steep temperature crossover existing in Y bB(12) between the low-temperature (Kondo insulator) and high-temperature (incoherent spin-fluctuation) regimes, which is rapidly suppressed by lighter Zr substitution. 相似文献
7.
P. Vonlanthen J.L. Gavilano B. Ambrosini H.R. Ott Y. Aoki H. Sugawara H. Sato 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,9(1):15-20
We report the results of 69Ga- and 71Ga-NMR measurements on NdGa2 at temperatures between 0.1 and and in applied magnetic fields between zero and 74 kOe. NdGa2 orders antiferromagnetically below and undergoes several metamagnetic transitions in external magnetic fields. In zero applied magnetic field and below the temperature dependence of the spin-lattice relaxation rate T1
-1
(
T
) shows a large linear-in-T term, about two orders of magnitude higher than for the reference compound LaGa2. This strong enhancement confirms the presence of low-energy excitations in the antiferromagnetic phase of NdGa2 as was previously indicated by specific heat data. Above , T1
-1
(
T
) is dominated by an exponential term, which we associate with excitations between the lowest energy levels of the f-electron system. The separation of these energy levels is determined by exchange, crystal-field and Zeeman interactions.
Received 3 September 1998 and Received in final form 3 November 1998 相似文献
8.
E. Albayrak 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(4):491-496
The thermal entanglement of a two-qubit anisotropic Heisenberg XXZ
chain with Dzyaloshinskii-Moriya (DM) interaction in an
inhomogeneous magnetic field was studied in detail. The effects of
the DM parameter, external magnetic field (B), a parameter b
which controls the inhomogeneity of B and the bilinear
interaction parameters Jx = Jy ≠ Jz (the anisotropic case) on
the concurrence (C) was formulated and studied in detail. The
behaviors of the concurrences for the cases between (J = Jz = 1) and
(J = -1,Jz = 1) and, (J = Jz = -1) and (J = 1,Jz = -1) at the ground
state and at the thermal equilibrium are exactly the same. It was
found that for the antiferromagnetic (AFM) case the entanglements
persist to higher temperatures in comparison with the ferromagnetic
(FM) case. In addition, the AFM case presents a special point at
which the nonzero concurrences are all equal at some special
temperatures. The further properties will be given in the text. 相似文献
9.
Hu CD 《J Phys Condens Matter》2012,24(8):086001
The Dzyaloshinskii-Moriya (DM) interaction in metals is an important mechanism for many magnetic properties. We start with the s-d exchange model and spin-orbit interaction for weak itinerant ferromagnetic systems to establish the form of DM interaction for metallic magnetic systems. The s-d exchange interaction is treated accurately and the conduction electron-mediated magnetism gives a form of DM interaction which is different from that in insulators. The implications of our result to spiral spin states and skyrmion lattices are also discussed. 相似文献
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11.
In this paper we calculate the thermal entanglement and teleportation in a two-qubit Heisenberg XYZ chain with the different Dzyaloshinskii-Moriya interaction and inhomogeneous magnetic fields. The analytical expressions of the concurrence and the average fidelity are obtained for this model. We have shown that the quantum phase transition occurs in the system and the quantum phase transition point depends on the inhomogeneity of magnetic fields. We compare the x-component Dzyaloshinskii-Moriya interaction with the z-component Dzyaloshinskii-Moriya interaction on the effects of quantum teleportation. It is found that we can take Dzyaloshinskii-Moriya interaction as one of the effective control parameters for the teleportation manipulation. 相似文献
12.
M. Loewenhaupt A. Metz N. M. Pyka D. McK. Paul J. Martin V. H. M. Duijn J. J. M. Franse H. Mutka W. Schmidt 《Annalen der Physik》1996,508(2):197-202
The low-energy magnetic excitations (?ω ≤ 2 meV) of polycrystalline samples of Nd2-xCexCuO4 with x = 0, 0.1 and 0.15 have been measured with high resolution inelastic neutron scattering using time-of-flight technique at temperatures below 0.3 K. All observed scattering originates from transitions within the ground state doublet of Nd3+. For Nd2CuO4 the response is inelastic, and shows at least three different modes, of which one is almost dispersionless. For x = 0.1 the excitation spectrum shifts towards lower energies, but the main features of the undoped compound are still visible, whereas for x = 0.15 the response is mainly quasi-elastic but remains localised in Q-space around the first magnetic Bragg point (0.5 0.5 1). A comparison with data obtained on a triple-axis-spectrometer on single crystals with x = 0.0 and x = 0.15 reveals that the response of the doped sample in the [0 0 1] direction is still inelastic. 相似文献
13.
D. C. Li Z. L. Cao 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(2):207-214
We investigate the entanglement in a two-qubit Heisenberg XYZ
system with different Dzyaloshinskii-Moriya (DM) interaction and
inhomogeneous magnetic field. It is found that the control
parameters (Dx, Bx and bx) are remarkably different
with the common control parameters (Dz, Bz and bz)
in the entanglement and the critical temperature, and these
x-component parameters can increase the entanglement and the
critical temperature more efficiently. Furthermore, we show the
properties of these x-component parameters for the control of
entanglement. In the ground state, increasing Dx (spin-orbit
coupling parameter) can decrease the critical value bxc and
increase the entanglement in the revival region, and adjusting
some parameters (increasing bx and J, decreasing Bx
and Δ) can decrease the critical value Dxc to enlarge
the revival region. In the thermal state, increasing Dx can
increase the revival region and the entanglement in the revival
region (for T or bx), and enhance the critical value
Bxc to make the region of high entanglement larger. Also, the
entanglement and the revival region will increase with the
decrease of Bx (uniform magnetic field). In addition, small
bx (nonuniform magnetic field) has some similar properties to
Dx, and with the increase of bx the entanglement also
has a revival phenomenon, so that the entanglement can exist at
higher temperature for larger bx. 相似文献
14.
Yong Zhang 《Journal of Physics and Chemistry of Solids》2008,69(1):111-115
The role of next-nearest-neighbor hopping interaction in determining the band structures and lattice configurations of combined polarons in pernigraniline-base polymer is explored on the basis of the Baranowski-Büttner-Voit (BBV) model. Numerical calculations show that the valence band extends to a larger range while the conduction band acts to the contrary, as the strength of the next-nearest-neighbor hopping interaction increases. The width of the Peierls gap and the number of the bound states trapped in have almost no changes. If the coupling strength β<0.15, the transition energy from the lower gap level to the higher one for a combined electron-polaron matches the long-lived 1.5 eV photoinduced absorption peak [J.M. Leng, R.P. McCall, K.R. Cromack, Y. Sun, S.K. Manohar, A.G. MacDiarmid, A.J. Epstein, Phys. Rev. B 48 (1993) 15719], and also supports the high temperature dispersion in the thermally stimulated depolarization current (TSDC) experiment [A.N. Papathanassiou, J. Grammatikakis, S. Sakkopoulos, E. Vitoratos, E. Dalas, J. Phys. Chem. Solids 63 (2002) 1771]. For a combined hole-polaron, new shallow level emerges when β∼0.12. 相似文献
15.
A symmetry analysis of the Dzyaloshinskii-Moriya (DM) interaction in MnSi-type crystals reveals a nontrivial antiferromagnetic pattern of tilted Mn moments remaining even after an unwinding of the ground-state helix by a strong magnetic field. The remaining tilts are caused by that component of the DM vector which is perpendicular to the component responsible for helical spiraling; both components are evaluated and related to the atomic structure using a simple model. It is shown that the tilting should induce pure magnetic reflections 00?(?=2n+1) in neutron or x-ray magnetic scattering. In addition, the DM-induced antiferromagnetic ordering is important for the core structure of intrinsic defects, for the spectra of magnetic resonances, and generally for a better understanding of spin-orbit interaction in this type of magnetics. 相似文献
16.
在非绝热近似下,研究了一维spin-Peierls系统中晶格量子涨落 对系统性质的影响,讨论了系统的二聚化相变、单粒子激发和双粒子束缚态. 结果表明,量子晶格涨落会抑制晶格的二聚化,破坏系统的spin-Peierls基态稳定性.在临界点,系统发生从二聚化spin-Peierls态向无能隙态的相变. 自旋声子耦合强度对束缚态能隙的影响比单粒子激发谱能隙显著.
关键词:
sin-Peierls系统
非绝热近似
玻色化
相图 相似文献
17.
Recent progress in the generation and spectroscopic application of femtosecond pulses in the wavelength range between 3 and 25 m has led to new insight into low-energy excitations of solids, in particular semiconductors, semiconductor nanostructures, and high-TC superconductors. The ultrafast nonequilibrium dynamics of such excitations has been observed in real-time and the underlying microscopic interactions have been analyzed. This article gives a brief overview of this exciting field of ultrafast science with the main emphasis on pulse generation and applications in semiconductor research where femtosecond intersubband Rabi flopping in quantum wells and quantum coherent electron transport in quantum cascade devices have been observed. PACS 78.67.De; 73.21.Fg; 07.57.Hm; 42.65.Re 相似文献
18.
In a quantum critical chain, the scaling regime of the energy and momentum of the ground state and low-lying excitations are described by conformal field theory (CFT). The same holds true for the von Neumann and Rényi entropies of the ground state, which display a universal logarithmic behavior depending on the central charge. In this Letter we generalize this result to those excited states of the chain that correspond to primary fields in CFT. It is shown that the nth Rényi entropy is related to a 2n-point correlator of primary fields. We verify this statement for the critical XX and XXZ chains. This result uncovers a new link between quantum information theory and CFT. 相似文献
19.
根据Milburn理论,研究了考虑内禀退相干情况下,三粒子XXZ海森堡系统在DzyaloshinskiiMoriya(DM)相互作用和各向异性参数的影响下的量子纠缠演化特性.分析了不同DM相互作用和內禀退相干因子等参数对量子对纠缠度的影响.研究表明:系统的对纠缠度与各向异性参数Δ无关,但DM相互作用和內禀退相干都对系统的对纠缠都有明显的影响.当无DM相互作用只存在內禀退相干时,系统的三对对纠缠度各不相同;引入DM相互作用后,系统的对纠缠度的稳定值将改变;选择合适的DM相互作用参数时,系统的对纠缠度随时间做震荡,随着时间的延长,震荡减弱至一个非零的稳定值;并且系统的对纠缠随內禀退相干增大,震荡幅度变小,震荡时间变短.因此,在內禀退相干存在时,合适的DM相互作用参数可以有效的控制对纠缠. 相似文献
20.
The bond-alternative ferromagnetic Ising model with the Dzyaloshinskii-Moriya (DM) interaction is investigated using an infinite time-evolving block decimation (iTEBD) algorithm, and two interesting phase diagrams are proposed. Without bond alternation, there are only two well-known phases (a ferromagnetic phase and an x-y spiral (chiral Luttinger liquid) phase). Once the bond alternation is taken into account, two additional interesting phases (a z-chiral and a z-stripe phases) are induced. Nonzero chiral order is observed in all phases except the ferromagnetic phase. Two kinds of chiral phase, with or without string order, are identified. With the y-axis DM interaction, the phase diagram becomes relatively simple, and consists of only two different phases (a ferromagnetic phase and a y-chiral phase). First-order metamagnetic phase transitions from the ferromagnetic phase into the other phases are observed in both cases. 相似文献