Bond-Alternation-Induced Topological Quantum Gaussian Transition and Topological Quantum Crossover in Ising Chains with the Dzyaloshinskii-Moriya Interaction

Many approaches to quantum gravity consider the revision of the space-time geometry and the structure of elementary particles. One of the main candidates is string theory. It is possible that this theory will be able to describe the problem of hierarchy, provided that there is an appropriate Calabi-Yau geometry. In this paper we will proceed from the traditional view on the structure of elementary particles in the usual four-dimensional space-time. The only condition is that quarks and leptons should have a common emerging structure. When a new formula for the mass of the hierarchy is obtained, this structure arises from topological quantum theory and a suitable choice of dimensional units.

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Topological quantum Lego

10.36471/jccm_march_2015_01 ◽

2015 ◽

Keyword(s):

Topological Quantum

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Topological Quantum Entanglement

10.21236/ada597621 ◽

2014 ◽

Author(s):

Sankar Das Sarma ◽

Michael Freedman ◽

Victor Galitski ◽

Chetan Nayak ◽

Kirill Shtengel

Keyword(s):

Quantum Entanglement ◽

Topological Quantum

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A topological quantum-chemical study of the chemisorption of carbon monoxide on the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19901907 ◽

1990 ◽

Vol 55 (8) ◽

pp. 1907-1919

Author(s):

Jiří Pancíř ◽

Ivana Haslingerová

Keyword(s):

Carbon Monoxide ◽

Quantum Chemical ◽

Co Adsorption ◽

Quantum Chemical Study ◽

Chemical Study ◽

Dissociative Chemisorption ◽

Frontier Orbitals ◽

Surface Sites ◽

Charged Surfaces ◽

Topological Quantum

A semiempirical quantum-chemical topological method is applied to the study of the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir and the nondissociative as well as dissociative chemisorption of carbon monoxide on them. On Ni, dissociative chemisorption is preferred to linear capture, whereas on Pd and Pt, linear capture is preferred although dissociative chemisorption is also feasible. On Rh and, in particular, on Ir, dissociative chemisorption is energetically prohibited. The high dissociative ability of the Ni surface can be ascribed to a rather unusual charge alteration and to the degeneracy of the frontier orbitals. Negative charges at the surface level are only found on the Ni and Pt surfaces whereas concentration of positive charges is established on the Rh and Ir surfaces; the Pd surface is nearly uncharged. Metals with negatively charged surfaces seem to be able to dissociate molecules of carbon monoxide. It is demonstrated that CO adsorption can take place on all metal surface sites, most effectively in the valley of the step. In all the cases studied, the attachment to the surface is found to be energetically more favourable for the carbon than for the oxygen.

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Computation and data driven discovery of topological phononic materials

Nature Communications ◽

10.1038/s41467-021-21293-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jiangxu Li ◽

Jiaxi Liu ◽

Stanley A. Baronett ◽

Mingfeng Liu ◽

Lei Wang ◽

...

Keyword(s):

High Throughput Screening ◽

Electronic System ◽

Nodal Line ◽

Data Driven ◽

Single Type ◽

Type I ◽

Structure Property ◽

Topological Quantum ◽

Data Driven Approach ◽

Spin Electronic

AbstractThe discovery of topological quantum states marks a new chapter in both condensed matter physics and materials sciences. By analogy to spin electronic system, topological concepts have been extended into phonons, boosting the birth of topological phononics (TPs). Here, we present a high-throughput screening and data-driven approach to compute and evaluate TPs among over 10,000 real materials. We have discovered 5014 TP materials and grouped them into two main classes of Weyl and nodal-line (ring) TPs. We have clarified the physical mechanism for the occurrence of single Weyl, high degenerate Weyl, individual nodal-line (ring), nodal-link, nodal-chain, and nodal-net TPs in various materials and their mutual correlations. Among the phononic systems, we have predicted the hourglass nodal net TPs in TeO3, as well as the clean and single type-I Weyl TPs between the acoustic and optical branches in half-Heusler LiCaAs. In addition, we found that different types of TPs can coexist in many materials (such as ScZn). Their potential applications and experimental detections have been discussed. This work substantially increases the amount of TP materials, which enables an in-depth investigation of their structure-property relations and opens new avenues for future device design related to TPs.

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Weyl, Dirac and high-fold chiral fermions in topological quantum matter

Nature Reviews Materials ◽

10.1038/s41578-021-00301-3 ◽

2021 ◽

Author(s):

M. Zahid Hasan ◽

Guoqing Chang ◽

Ilya Belopolski ◽

Guang Bian ◽

Su-Yang Xu ◽

...

Keyword(s):

Quantum Matter ◽

Topological Quantum

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Dzyaloshinskii–Moriya interaction in noncentrosymmetric superlattices

npj Computational Materials ◽

10.1038/s41524-021-00592-8 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Woo Seung Ham ◽

Abdul-Muizz Pradipto ◽

Kay Yakushiji ◽

Kwangsu Kim ◽

Sonny H. Rhim ◽

...

Keyword(s):

Heavy Metal ◽

Degrees Of Freedom ◽

Orbit Coupling ◽

Inversion Symmetry ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Band Formation ◽

Research Activities ◽

Moriya Interaction

AbstractDzyaloshinskii–Moriya interaction (DMI) is considered as one of the most important energies for specific chiral textures such as magnetic skyrmions. The keys of generating DMI are the absence of structural inversion symmetry and exchange energy with spin–orbit coupling. Therefore, a vast majority of research activities about DMI are mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report an asymmetric band formation in a superlattices (SL) which arises from inversion symmetry breaking in stacking order of atomic layers, implying the role of bulk-like contribution. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin–orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Our work provides more degrees of freedom to design chiral magnets for spintronics applications.

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