scholarly journals Quantum spiral spin-tensor magnetism

2020 ◽  
Vol 101 (14) ◽  
Author(s):  
Xiaofan Zhou ◽  
Xi-Wang Luo ◽  
Gang Chen ◽  
Suotang Jia ◽  
Chuanwei Zhang
Keyword(s):  
2021 ◽  
Vol 16 (5) ◽  
Author(s):  
Xu-Ping Yao ◽  
Jian Qiao Liu ◽  
Chun-Jiong Huang ◽  
Xiaoqun Wang ◽  
Gang Chen
Keyword(s):  

2016 ◽  
Vol 40 ◽  
pp. 1660098
Author(s):  
K. Heinemann ◽  
D. P. Barber ◽  
J. A. Ellison ◽  
M. Vogt

We give an informal summary of ongoing work which uses tools distilled from the theory of fibre bundles to classify and connect invariant fields associated with spin motion in storage rings. We mention four major theorems. One ties invariant fields with the notion of normal form, the second allows comparison of different invariant fields and the two others tie the existence of invariant fields to the existence of certain invariant sets. We explain how the theorems apply to the spin dynamics of spin-[Formula: see text] and spin-[Formula: see text] particles. Our approach elegantly unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics and suggests an avenue for addressing the question of the existence of the invariant spin field.


2007 ◽  
Vol 1034 ◽  
Author(s):  
V. A. Khomchenko ◽  
D. A. Kiselev ◽  
J. M. Vieira ◽  
Li Jian ◽  
A. M. L. Lopes ◽  
...  

AbstractInvestigation of crystal structure, magnetic and local ferroelectric properties of the diamagnetically-doped Bi1−xAxFeO3 (A= Ca, Sr, Pb, Ba; x= 0.2, 0.3) ceramic samples has been carried out. It has been shown that the solid solutions have a rhombohedrally distorted perovskite structure described by the space group R3c. Piezoresponse force microscopy data have revealed the existence of the spontaneous ferroelectric polarization in the samples at room temperature. Magnetization measurements have shown that the magnetic state of these compounds is determined by the ionic radius of the substituting elements. A-site substitution with the biggest ionic radius ions has been found to suppress the spiral spin structure of BiFeO3 and to result in the appearance of weak ferromagnetism. The magnetic properties have been discussed in terms of doping- induced changes in the magnetic anisotropy.


Author(s):  
S. Alireza Momeni ◽  
Mohsen Asghari

In Hypo-elastic constitutive models an objective rate of the Cauchy stress tensor is expressed in terms of the current state of the stress and the deformation rate tensor D in a way that the dependency on the latter is a homogeneously linear one. In this work, a type of grade-one hypo-elastic models (i.e. models with linear dependency of the hypo-elasticity tensor on the stress) is considered for isotropic materials based on the objective corotational rates of stress. A positive real parameter denoted by n is involved in the considered type. Different values can be selected for this parameter, each selection leads to a specific model within the class of grade-one hypo-elasticity. The spin of the associated corotational rate is also dependent on the parameter n. In the special case of n=0, the corresponding hypo-elastic model reduces to a grade-zero one with the logarithmic rate of stress; noting that this rate is a corotational rate associated with the logarithmic spin tensor. Moreover, by choosing n=2, the model reduces to a grade-one hypo-elastic model with the Jaumann rate, i.e. the corotational rate associated with the vorticity spin tensor. As case studies, the simple shear problem is investigated with utilizing the considered type of hypo-elastic models with various values for parameter n, and the curves for the stress-shear response are depicted.


2007 ◽  
Vol 75 (10) ◽  
Author(s):  
M. Matsuda ◽  
M. Takeda ◽  
M. Nakamura ◽  
K. Kakurai ◽  
A. Oosawa ◽  
...  
Keyword(s):  

1999 ◽  
Vol 16 (11) ◽  
pp. 3483-3496 ◽  
Author(s):  
A Yu Segal ◽  
A A Sharapov

1970 ◽  
Vol 25 (26) ◽  
pp. 1761-1764 ◽  
Author(s):  
Tadashi Arai
Keyword(s):  

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