Strain-Controlled Magnetic Ordering in 2D Carbon Metamaterials

离子注入超材料中的磁织构控制

Magnetic texture control in ion-implanted metamaterials

本研究实验探究增材制造对Fe$^+$注入Pd人工自旋冰的影响，发现其有序温度更高，归因于不均匀Fe浓度与磁性深度分布，为超材料静态和动态性质微调提供新自由度。

Tunable electronic and magnetic properties of thin Nb$_3$I$_8$ nanofilms: interplay between strain and thickness

The study of novel 2D platforms implementing magnetism in tunable van der Waals (vdW) homo- and hetero-structures paves the way to innovative spintronics and magnetic devices. In this study, we unravel the intriguing properties of few-layer Nb$_3$I$_8$ vdW nanofilms from first principles, showing how and to what extent specific magnetic orderings can be tuned using several degrees of freedom, such as film thickness, stacking geometry, and strain or even a combination of them. All these aspects are explored here, giving a comprehensive view of this novel and promising magnetic material.

Non-Abelian SU(2) gauge fields through density-wave order and strain in graphene

Spatially varying strain patterns can qualitatively alter the electronic properties of graphene, acting as effective valley-dependent magnetic fields and giving rise to pseudo-Landau-level (PLL) quantization. Here, we show that the strain-induced magnetic field is one component of an SU(2) non-Abelian gauge field within the low-energy theory of graphene, and identify the other two components as period-3 charge-density waves. We show that these density-waves, if spatially varied, give rise to PLL quantization. We also argue that strain-induced magnetic fields can induce density-wave order in gr…

磁超材料中的涌现三临界性

Emergent tri-criticality in magnetic metamaterials

该研究通过变长度介观自旋模型数值研究方形排列磁性圆盘构成的磁超材料，发现从Kosterlitz-Thouless到一级相变经由三临界点的有序转变，并探讨了实验意义。

Enhancement of magnetic ordering by the stress fields of grain boundaries in ferromagnets

In the paper we predict a distinctive change of magnetic properties and considerable increase of the Curie temperature caused by the strain fields of grain boundaries in ferromagnetic films. It is shown that a sheet of spontaneous magnetization may arise along a grain boundary at temperatures greater than the bulk Curie temperature. The temperature dependence and space distribution of magnetization in a ferromagnetic film with grain boundaries are calculated. We found that $45^\circ$ grain boundaries can produce long-range strain fields that results in the width of the magnetic sheet along the…

Dynamics and ordering of the nucleationless island formation in heteroepitaxy

We study the morphological evolution of strained islands in growing crystal films by use of a continuum description including wetting, elasticity and deposition flux. Wetting breaks translational invariance, allowing the flux to tune different nonlinear regimes. Increasing the flux, we find first an annealing-like dynamics, then a slower but non-conventional ripening followed by a steady regime, while the island density continuously increases. The islands develop spatial correlations and ordering with a narrow two-peaked distance distribution and ridge-like clusters of islands for high flux.

Lattice Disorder Effect on Magnetic Ordering of Iron Arsenides

This study investigates the changes of magnetic ordering temperature via nano- and mesoscale structural features in an iron arsenide. Although magnetic ground states in quantum materials can be theoretically predicted from known crystal structures and chemical compositions, the ordering temperature is harder to pinpoint due to such local lattice variations. In this work we find surprisingly that a locally disordered material can exhibit a significantly larger Neel temperature (TN) than an ordered material of precisely the same chemical stoichiometry. Here, a EuFe2As2 crystal, which is a 122 pa…