Magneto-optical conductivity of double Weyl semimetals

We report on an experimental study of current induced switching in perpendicular magnetic random access memory (MRAM) cells with variable resistance-area products (RAs). Our results show that in addition to spin transfer torque (STT), current induced self-heating and voltage controlled magnetic anisotropy also contribute to switching and can explain the RA dependencies of switching current density and STT efficiency. Our findings suggest that thermal optimization of perpendicular MRAM cells can result in significant reduction of switching currents.

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“…Eq. (4) is commonly found in the literature 12,17,18 where only STT influence is accounted for, while Eq. 4) and (5).…”

Section: Results and Analysismentioning

confidence: 99%

Origin of the Resistance-Area-Product Dependence of Spin-Transfer-Torque Switching in Perpendicular Magnetic Random-Access Memory Cells

et al. 2020

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“…In later investigations, various modified versions of the CL are proposed [69][70][71][72][73][74][75][76][77][78][79], and also realized experimentally in atom-optical setups like photonic lattices [80,81] and cold atoms [82,83]. Intriguing topological features of the CL are reflected in the formation of AB cages [81] and the quantized Thouless pumping [84].…”

Section: The Modelmentioning

confidence: 99%

“…One version of the modified CL model concerns the case with spin-1/2 fermions and spin-orbit couplings in the ladder. Recently, such kinds of spinful CL (SCL) have been investigated in several studies [84][85][86]. It was found that the existence of spin degrees of freedom could not only modify the symmetry classification of the CL (e.g., from AIII to CII), but also induce new topological transport phenomena.…”

Section: The Modelmentioning

confidence: 99%

Floquet topological phases with fourfold-degenerate edge modes in a driven spin-1/2 Creutz ladder

Zhou

2020

Phys. Rev. A

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Floquet engineering has the advantage of generating new phases with large topological invariants and many edge states by simple driving protocols. In this work, we propose an approach to obtain Floquet edge states with fourfold degeneracy and even-integer topological characterizations in a spinful Creutz ladder model, which is realizable in current experiments. Putting the ladder under periodic quenches, we found rich Floquet topological phases in the system, which belong to the symmetry class CII. Each of these phases is characterized by a pair of even integer topological invariants (w0, wπ) ∈ 2Z × 2Z, which can take arbitrarily large values with the increase of driving parameters. Under the open boundary condition, we further obtain multiple quartets of topological edge states with quasienergies zero and π in the system. Their numbers are determined by the bulk topological invariants (w0, wπ) due to the bulk-edge correspondence. Finally, we propose a way to dynamically probe the Floquet topological phases in our system by measuring a generalized mean chiral displacement. Our findings thus enrich the family of Floquet topological matter, and put forward the detection of their topological properties. arXiv:1912.09078v1 [cond-mat.mes-hall]

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“…However, the BSE is computational formidable and has not yet widely applied in water. This computational burden has been greatly alleviated by the recently introduced approximate BSE solution utilizing localized basis [28][29][30]. On the other hand, the modeling of water at the molecular level is no less difficult because of the nature of the H-bond, which is a balance of many physical interactions.…”

mentioning

confidence: 99%

“…Moreover, compared to the bound exciton described by the pre-edge, the main-and post-edge contributions to the XAS spectrum are resonant excited states, which are sensitive to the intermediate-range and long-range ordering of H-bond network. Hence, a much larger simulation super cell is required to properly describe these delocalized excited states [30].…”

mentioning

confidence: 99%

Electron-Hole Theory of the Effect of Quantum Nuclei on the X-Ray Absorption Spectra of Liquid Water

et al. 2018

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Electron-hole excitation theory is used to unveil the role of nuclear quantum effects on the X-ray absorption spectral signatures of water, whose structure is computed via path-integral molecular dynamics with the MB-pol intermolecular potential model. Compared to spectra generated from the classically modeled water, quantum nuclei introduce important effects on the spectra in terms of both the energies and line shapes. Fluctuations due to delocalized protons influence the short-range ordering of the hydrogen bond network via changes in the intramolecular covalence, which broaden the pre-edge spectra. For intermediate-range and long-range ordering, quantum nuclei approach the neighboring oxygen atoms more closely than classical protons, promoting an "ice-like" spectral feature with the intensities shifted from the main-to post-edge. Computed spectra are in nearly quantitative agreement with the available experimental data.

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Magneto-optical conductivity of double Weyl semimetals

Cited by 33 publications

References 68 publications

Origin of the Resistance-Area-Product Dependence of Spin-Transfer-Torque Switching in Perpendicular Magnetic Random-Access Memory Cells

Origin of the Resistance-Area-Product Dependence of Spin-Transfer-Torque Switching in Perpendicular Magnetic Random-Access Memory Cells

Floquet topological phases with fourfold-degenerate edge modes in a driven spin-1/2 Creutz ladder

Electron-Hole Theory of the Effect of Quantum Nuclei on the X-Ray Absorption Spectra of Liquid Water

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