We perform a comparative study of spin pumping in NiO/Ni[Formula: see text]Fe[Formula: see text] (Py) by altering the crystallinity of NiO. We simultaneously grow high-quality NiO/Py heterostructures on Si/SiO2 and Al2O3(0001) substrates. Although the growth on Si/SiO2 substrate produced polycrystalline NiO (Poly-NiO), the growth on Al2O3(0001) substrate produced epitaxial NiO (Epi-NiO). Our ferromagnetic resonance measurements reveal the presence of two-magnon scattering (TMS) in the measured linewidth for the Epi-NiO/Py system. By carefully considering the contribution of TMS, we found the effective spin mixing conductance, g[Formula: see text] to be comparable in both Poly-NiO/Py and Epi-NiO/Py, despite the different crystallinity of NiO. Our findings show that g[Formula: see text] of an optimized polycrystalline-NiO/Py system can reach the value for an epitaxial-NiO/Py system.

By using the density functional theory, we have studied the electronic structure and magnetism of the oxygen vacancy defect in GdCoO3 perovskite compound. We have carried out a magnetic stability calculation; between many possible magnetic configurations, the ferromagnetic ordering was predicted in both gadolinium and cobalt sublattices. We have demonstrated that the oxygen vacancy defect causes a ferromagnetic order via a mixture of octahedral HS Co[Formula: see text], tetrahedral HS Co[Formula: see text] and octahedral IS Co[Formula: see text]. From the spin magnetic moment and partial density of state investigation, we have predicted an induced long-range ferromagnetic ordering in nonstoichiometric GdCoO[Formula: see text].

SPINOnline Ready No AccessErratum: Unveiling Phase Transitions in 1D Systems with Short-Range Interactionsis erratum ofUnveiling Phase Transitions in 1D Systems with Short-Range InteractionsL. S. Ferreira, L. N. Jorge, Cláudio J. DaSilva, Minos A. Neto, and A. A. CaparicaL. S. FerreiraInstituto de Física, Universidade Federal de Goiás, Av. Esperança s/n, CEP 74690-900, Goiânia, GO, Brazil, L. N. JorgeInstituto Federal do Mato Grosso Campus Cáceres - Prof. Olegário Baldo Av. dos Ramires s/n, 78200-000, Cáceres, MT, Brazil, Cláudio J. DaSilvaInstituto Federal de Goiás, Rua 76, Centro, Goiânia - GO, Brazil, Minos A. NetoDepartamento de Física, Universidade Federal do Amazonas 3000, Japiim, 69077-000, Manaus-AM, Brazil, and A. A. CaparicaInstituto de Física, Universidade Federal de Goiás, Av. Esperança s/n, CEP 74690-900, Goiânia, GO, BrazilCorresponding author.https://doi.org/10.1142/S2010324723920017Cited by:0 Next AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail View article[SPIN, Vol. 12, No. 4 (2022) 2250026 (9 pages), https://doi.org/10.1142/S2010324722500266] FiguresReferencesRelatedDetailsRelated articlesUnveiling Phase Transitions in 1D Systems with Short-Range Interactions26 Nov 2022SPIN Recommended Online Ready Metrics History Published: 31 March 2023 PDF download

In this work, we model the salient magnetic properties of the alloy lamellar ferrimagnetic nanostructures [Formula: see text] between [Formula: see text] semiinfinite leads. We have employed the Ising spin effective field theory (EFT) to compute the reliable magnetic exchange constants for the pure cobalt [Formula: see text] and gadolinium [Formula: see text] materials in complete agreement with their experimental data. The sublattice magnetizations of the [Formula: see text] and [Formula: see text] sites on the individual hcp atomic (0001) planes of the Co–Gd layered nanostructures are computed for each plane and corresponding sites by using the combined EFT and mean field theory (MFT) spin methods. The sublattice magnetizations, effective site magnetic moments, and ferrimagnetic compensation characteristics for the individual hcp atomic planes of the embedded nanostructures, are computed as a function of temperature, and for various stable eutectic concentrations in the range [Formula: see text]. The theoretical results for the sublattice magnetizations and the local magnetic variables of these ultrathin ferrimagnetic lamellar nanostructured systems, between cobalt leads, are necessary for the study of their magnonic transport properties, and eventually their spintronic dynamic computations. The method developed in this work is general and can be applied to comparable magnetic systems nanostructured with other materials.

In this study, we investigated the dielectric properties of ovalene-like nanostructure with RKKY (Ruderman–Kittel–Kasuya–Yoshida) interactions, using Monte Carlo simulations. Nanosystem consists of an ovalene-like nanostructure with mixed spins [Formula: see text]-7/2 and S-1, separated by non-electric layers (NEL). We investigated the effect of the non-electric layers, external longitudinal electric field and ferrielectric exchange coupling on polarization and dielectric susceptibility of the nanostructure. We find that the transition temperature is affected by an increase in the number of non-electrical layers. These results can enrich the dielectric properties of ovalene-like nanostructure for future nanotechnology applications.

The statement that any phase transition is related to the appearance or disappearance of long-range spatial correlations and precludes a finite transition temperature in one-dimensional (1D) systems is rooted in condensed matter theory. In this paper, we demonstrate that the 1D Ising model with short-range exchange interactions exhibits a second-order phase transition at a finite temperature relying on the proper choice of the order parameter. We combined analytical calculations and high-precision entropic sampling simulations and chose a slightly different order parameter, namely, the modulus of the magnetization. Notably, we detected a phase transition with a corresponding critical temperature around 15 K, which is in excellent agreement with experimental results. Our study indicates that the incorrect choice of the order parameter may mask phase transitions in 1D systems.

In this work, the Monte Carlo simulations have been performed to investigate the magnetic properties of the kesterite and the stannite nanostructures with mixed spins. The Blume–Capel model has been adopted to study the Cu2ZnSnSe4 nanostructures. Furthermore, we have examined different transitions as a function of the temperature, the crystal field, and the exchange coupling interactions. Also, the behavior of the magnetizations and magnetic susceptibilities are investigated as a function of the different physical parameters. A comparison of the magnetic properties of each nanostructure has been studied and discussed.

SPINVol. 11, No. 04, 2199001 (2021) Free AccessAuthor Index Volume 11 (2021)https://doi.org/10.1142/S2010324721990010Cited by:0 Previous AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetails Recommended Vol. 11, No. 04 Metrics History PDF download

Deutsch–Jozsa problem (D–J) has exact quantum 1-query complexity (“exact” means no error), but requires super-exponential queries for the optimal classical deterministic decision trees. D–J problem is equivalent to a symmetric partial Boolean function, and in fact, all symmetric partial Boolean functions having exact quantum 1-query complexity have been found out and these functions can be computed by D–J algorithm. A special case is that all symmetric Boolean functions with exact quantum 1-query complexity follow directly and these functions are also all total Boolean functions with exact quantum 1-query complexity obviously. Then there are pending problems concerning partial Boolean functions having exact quantum 1-query complexity and new results have been found, but some problems are still open. In this paper, we review these results regarding exact quantum 1-query complexity and in particular, we also obtain a new result that a partial Boolean function with exact quantum 1-query complexity is constructed and it cannot be computed by D–J algorithm. Further problems are pointed out for future study.