scholarly journals Electric activity at magnetic moment fragmentation in spin ice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. I. Khomskii
Keyword(s):  
Electric Field ◽  
Magnetic Moment ◽  
Domain Walls ◽  
Electric Activity ◽  
Magnetic Monopoles ◽  
Partial Ordering ◽  
Spin Ice ◽  
Electric Dipoles ◽  
The Moment ◽  
Local Defects

AbstractSpin ice systems display a variety of very nontrivial properties, the most striking being the existence in them of magnetic monopoles. Such monopole states can also have nontrivial electric properties: there exist electric dipoles attached to each monopole. A novel situation is encountered in the moment fragmentation (MF) state, in which monopoles and antimonopoles are perfectly ordered, whereas spins themselves remain disordered. We show that such partial ordering strongly modifies the electric activity of such systems: the electric dipoles, which are usually random and dynamic, become paired in the MF state in (d, −d) pairs, thus strongly reducing their electric activity. The electric currents existing in systems with noncoplanar spins are also strongly influenced by MF. We also consider modifications in dipole and current patterns in magnetic textures (domain walls, local defects) and at excitations with nontrivial dynamics in a MF state, which show very rich behaviour and which could in principle allow to control them by electric field.

POLARON IN A QUANTUM DOT UNDER AN ELECTRIC FIELD

2007 ◽  
Vol 21 (24) ◽  
pp. 1635-1642
Author(s):  
MIAN LIU ◽  
WENDONG MA ◽  
ZIJUN LI
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Field Intensity ◽  
Ground State Energy ◽  
Ground State ◽  
Electric Field Intensity ◽  
State Energy ◽  
Theoretical Study ◽  
The Moment ◽  
Transformation Methods

We conducted a theoretical study on the properties of a polaron with electron-LO phonon strong-coupling in a cylindrical quantum dot under an electric field using linear combination operator and unitary transformation methods. The changing relations between the ground state energy of the polaron in the quantum dot and the electric field intensity, restricted intensity, and cylindrical height were derived. The numerical results show that the polar of the quantum dot is enlarged with increasing restricted intensity and decreasing cylindrical height, and with cylindrical height at 0 ~ 5 nm , the polar of the quantum dot is strongest. The ground state energy decreases with increasing electric field intensity, and at the moment of just adding electric field, quantum polarization is strongest.

Deepening of domains at e-beam writing on the -Z surface of lithium niobate

2021 ◽  
Author(s):  
Lyudmila Kokhanchik ◽  
Evgenii Emelin ◽  
Vadim Vladimirovch Sirotkin ◽  
Alexander Svintsov
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Lithium Niobate ◽  
Electric Field ◽  
Domain Walls ◽  
Normal Component ◽  
Beam Current ◽  
Near Surface ◽  
Domain Structures ◽  
Sign Inversion

Abstract The focus of the study was to investigate the peculiarities of the domains created by electron beam (e-beam) in a surface layer of congruent lithium niobate, which comparable to a depth of electron beam charge penetration. Direct e-beam writing (DEBW) of different domain structures with a scanning electron microscope was performed on the polar -Z cut. Accelerating voltage 15 kV and e-beam current 100 pA were applied. Different patterns of local irradiated squares were used to create domain structures and single domains. No domain contrast was observed by the PFM technique. Based on chemical etching, it was found that the vertices of the domains created do not reach the surface level. The average deepening of the domain vertices was several hundred nanometers and varied depending on the irradiation dose and the location of the irradiated areas (squares) relative to each other. Computer simulation was applied to analyze the spatial distribution of the electric field in the various irradiated patterns. The deepening was explained by the fact that in the near-surface layer there is a sign inversion of the normal component of the electric field strength vector, which controls the domain formation during DEBW. Thus, with the help of e-beam, domains were created completely located in the bulk, in contrast to the domains that are nucleated on the surface of the -Z cut during the polarization inversion with AFM tip. The detected deepening of e-beam domains suggests the possibility of creating the “head-to-head” domain walls in the near-surface layer lithium niobate by DEBW.

Electric Field Distribution Analysis of ±1000kV DC Wall Bushing during Polarity Reversal

2012 ◽  
Vol 229-231 ◽  
pp. 807-810
Author(s):  
Li Zhang ◽  
Qing Min Li ◽  
Li Na Zhang ◽  
Yu Di Cong
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Potential Distribution ◽  
Electric Field Distribution ◽  
Polarity Reversal ◽  
Distribution Analysis ◽  
The Finite Element Method ◽  
Insulation System ◽  
The Moment ◽  
Short Time

±1000kV DC wall bushing under planning is a complex insulation system which bears the effects imposed by different working conditions. The electric field distribution is concentrated at the bushing outlet terminal, which might result in breakdown discharge especially when short-time abrupt conditions such as polarity reversal occur. In this paper, the finite element method is utilized to analyze electric field distribution and potential distribution of wall bushing during polarity reversal. Electric field distribution and potential distribution at the moment of polarity reversal are obtained, which provides value reference for the study of polarity reversal process.

Ferroelectric domain-wall logic units

2021 ◽  
Author(s):  
Jing Wang ◽  
Jing Ma ◽  
Houbing Huang ◽  
Ji Ma ◽  
Hasnain Jafri ◽  
...  
Keyword(s):  
Domain Wall ◽  
Electric Field ◽  
Domain Walls ◽  
Logic Gates ◽  
Piezoresponse Force Microscopy ◽  
Ferroelectric Domain ◽  
Conduction Path ◽  
Conductive Atomic Force Microscopy ◽  
Flexible Control ◽  
Force Microscopy

Abstract The electronic conductivities of ferroelectric domain walls have been extensively explored over the past decade for potential nanoelectronic applications. However, the realization of logic devices based on ferroelectric domain walls requires reliable and flexible control of the domain-wall configuration and conduction path. Here, we demonstrate electric-field-controlled stable and repeatable on-and-off switching of conductive domain walls within topologically confined vertex domains naturally formed in self-assembled ferroelectric nano-islands. Using a combination of piezoresponse force microscopy, conductive atomic force microscopy, and phase-field simulations, we show that on-off switching is accomplished through reversible transformations between charged and neutral domain walls via electric-field-controlled domain-wall reconfiguration. By analogy to logic processing, we propose programmable logic gates (such as NOT, OR, AND and their derivatives) and logic circuits (such as fan-out) based on reconfigurable conductive domain walls. Our work provides a potentially viable platform for programmable all-electric logic based on a ferroelectric domain-wall network with low energy consumption.

scholarly journals Piezoelectricity in perovskite-type pseudo-cubic ferroelectrics by partial ordering of off-centered cations

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Yoshihiro Kuroiwa ◽  
Sangwook Kim ◽  
Ichiro Fujii ◽  
Shintaro Ueno ◽  
Yuki Nakahira ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Partial Ordering ◽  
Ferroelectric Ceramics ◽  
Piezoelectric Response ◽  
X Ray Diffraction ◽  
Cubic Symmetry ◽  
X Ray ◽  
Domain Structures ◽  
Perovskite Type

Abstract A large piezoelectric response in ferroelectric ceramics is typically associated with extrinsic contributions from ferroelectric domain structures. However, such domain structures cannot be expected in systems with pseudo-cubic symmetry. In this study, we determine the mechanism of significant piezoelectricity and ferroelectricity in 0.3BaTiO3–0.1Bi(Mg1/2Ti1/2)O3–0.6BiFeO3 ceramic with a perovskite-type pseudo-cubic symmetry. Synchrotron radiation X-ray diffraction reveals that the Bi ions in this ceramic essentially prefer to be off-centered at six sites by approximately 0.4 Å, in the cubic <100> directions. A phase transition occurs at TC ~725 K. However, the crystal seems to present a cubic symmetry even at room temperature. The large piezoelectric response is caused by the combinational partial ordering of the off-centered Bi ions, adapted to any direction of the applied electric field to the ceramic grains. The proposed mechanism for the emergence of a high polarization in the above system will enable designing novel Pb-free ceramics by controlling the fluctuated and off-centered ions under an applied electric field.

scholarly journals Electroinduced magnetic bubble domain nucleation

2018 ◽  
Vol 185 ◽  
pp. 07001
Author(s):  
Daria Kulikova ◽  
Timur Gareev ◽  
Elena Nikolaeva ◽  
Alexander Pyatakov
Keyword(s):  
Electric Field ◽  
Domain Walls ◽  
Electric Field Pulse ◽  
Magnetic Bias ◽  
Field Pulse ◽  
Magnetic Bubble ◽  
Garnet Films ◽  
Magnetoelectric Properties ◽  
Iron Garnet

The magnetoelectric properties of micromagnetic structures in iron garnet films manifest themselves in electrically induced displacement of domain walls and magnetic bubble domains nucleation. In this paper we found the condition of the electrically induced bubble domain nucleation in terms of critical electric field, magnetic bias and temperature. The collapse of magnetic bubble domain under the action of electric field pulse is also demonstrated.

scholarly journals Magnetic monopoles in spin ice

Nature ◽  
2008 ◽  
Vol 451 (7174) ◽  
pp. 42-45 ◽  
Author(s):  
C. Castelnovo ◽  
R. Moessner ◽  
S. L. Sondhi
Keyword(s):  
Magnetic Monopoles ◽  
Spin Ice

Domain Dynamics of C-Axis Polarization in Bismuth Titanate Crystals

2007 ◽  
Vol 350 ◽  
pp. 69-72 ◽  
Author(s):  
Yuuki Kitanaka ◽  
Yuji Noguchi ◽  
Masaru Miyayama
Keyword(s):  
Electric Field ◽  
Remanent Polarization ◽  
Bismuth Titanate ◽  
Domain Walls ◽  
Polarization Switching ◽  
Optical Microscope ◽  
Saturated Polarization ◽  
Domain State ◽  
Initial Nucleus ◽  
Domain Dynamics

Polarization switching and domain dynamics in unpoled and poled crystals of bismuth titanate by applying electric field along the crystallographic c axis were investigated through polarization measurements and domain observations by optical microscope and piezoelectric force microscope. Poled crystals showed a well-saturated polarization hysteresis with a remanent polarization of 4.4 μC/cm2 and a coercive field of 4.7 kV/cm. Domain observations reveal that lenticular domain acts as an initial nucleus during polarization switching. The sidewise motion of the lenticular-domain walls and resultant single domain state were easily established for the poled crystals, while the lenticular domains observed in unpoled crystals were clamped even though a high electric field was applied to them.

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