Topological properties and dynamics of magnetic skyrmions

2013 ◽  
Vol 8 (12) ◽  
pp. 899-911 ◽  
Author(s):  
Naoto Nagaosa ◽  
Yoshinori Tokura
2021 ◽  
Author(s):  
Rajesh Kumar Rajagopal

Magnetic skyrmions are small whirling topological defects in a texture magnetization state. Their stabilization and dynamics depend strongly on their topological properties. Skyrmions are induced by non-centrosymmetric crystal structure of magnetic compounds and thin films. Skyrmions are extremely small, with diameters in the nanometer range, and behave as particles that can be created, moved and annihilated. This makes them suitable for information storage and logic technologies. Skyrmions had been observed only at low temperature, and mostly under large applied magnetic fields. An intense research in this field has led to the identification of skyrmions in thin-film and multilayer structures in these heterostrutres skyrmions are able to survive at room temperature and can be manipulated by electrical currents. Utilizing interlayer magnetic exchange bias with synthetic antiferromagnet with can be used to isolated antiferromagnetic skyrmions at room temperature. The development of skyrmion-based topological spintronics holds promise for applications in the writing, processing and reading functionalities at room temperature and can be extended further to all-electrical manipulation spintronics.


Author(s):  
Norman Davidson

The basic protein film technique for mounting nucleic acids for electron microscopy has proven to be a general and powerful tool for the working molecular biologist in characterizing different nucleic acids. It i s possible to measure molecular lengths of duplex and single-stranded DNAs and RNAs. In particular, it is thus possible to as certain whether or not the nucleic acids extracted from a particular source are or are not homogeneous in length. The topological properties of the polynucleotide chain (linear or circular, relaxed or supercoiled circles, interlocked circles, etc. ) can also be as certained.


2013 ◽  
Vol 45 (12) ◽  
pp. 1324-1333
Author(s):  
Baolin LI ◽  
Youguo CHEN ◽  
Xiangyong YUAN ◽  
Jackson Todd ◽  
Xiting HUANG

2020 ◽  
Vol 16 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Süleyman Ediz ◽  
Murat Cancan

Background: Reckoning molecular topological indices of drug structures gives the data about the underlying topology of these drug structures. Novel anticancer drugs have been leading by researchers to produce ideal drugs. Materials and Methods: Pharmacological properties of these new drug agents explored by utilizing simulation strategies. Topological indices additionally have been utilized to research pharmacological properties of some drug structures. Novel alkylating agents based anticancer drug candidates and ve-degree molecular topological indices have been introduced recently. Results and Conclusion: In this study we calculate ve-degree atom-bond connectivity, harmonic, geometric-arithmetic and sum-connectivity molecular topological indices for the newly defined alkylating agents based dual-target anticancer drug candidates.


1994 ◽  
Vol 20 (2) ◽  
pp. 819
Author(s):  
Muthuvel

2013 ◽  
Vol 41 (2) ◽  
pp. 548-553 ◽  
Author(s):  
Andrew A. Travers ◽  
Georgi Muskhelishvili

How much information is encoded in the DNA sequence of an organism? We argue that the informational, mechanical and topological properties of DNA are interdependent and act together to specify the primary characteristics of genetic organization and chromatin structures. Superhelicity generated in vivo, in part by the action of DNA translocases, can be transmitted to topologically sensitive regions encoded by less stable DNA sequences.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anthony K. C. Tan ◽  
Pin Ho ◽  
James Lourembam ◽  
Lisen Huang ◽  
Hang Khume Tan ◽  
...  

AbstractMagnetic skyrmions are nanoscale spin textures touted as next-generation computing elements. When subjected to lateral currents, skyrmions move at considerable speeds. Their topological charge results in an additional transverse deflection known as the skyrmion Hall effect (SkHE). While promising, their dynamic phenomenology with current, skyrmion size, geometric effects and disorder remain to be established. Here we report on the ensemble dynamics of individual skyrmions forming dense arrays in Pt/Co/MgO wires by examining over 20,000 instances of motion across currents and fields. The skyrmion speed reaches 24 m/s in the plastic flow regime and is surprisingly robust to positional and size variations. Meanwhile, the SkHE saturates at ∼22∘, is substantially reshaped by the wire edge, and crucially increases weakly with skyrmion size. Particle model simulations suggest that the SkHE size dependence — contrary to analytical predictions — arises from the interplay of intrinsic and pinning-driven effects. These results establish a robust framework to harness SkHE and achieve high-throughput skyrmion motion in wire devices.


ACS Nano ◽  
2021 ◽  
Author(s):  
Jilei Chen ◽  
Junfeng Hu ◽  
Haiming Yu

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