Abstract
The quantum spin liquid is a highly entangled magnetic state characterized by the absence of static magnetism in its ground state. Instead, the spins fluctuate in a highly correlated way ...down to the lowest temperatures. Quantum spin liquids are very rare and are confined to a few specific cases where the interactions between the magnetic ions cannot be simultaneously satisfied (known as frustration). Lattices with magnetic ions in triangular or tetrahedral arrangements, which interact via isotropic antiferromagnetic interactions, can generate such a frustration. Three-dimensional isotropic spin liquids have mostly been sought in materials where the magnetic ions form pyrochlore or hyperkagome lattices. Here we present a three-dimensional lattice called the hyper-hyperkagome that enables spin liquid behaviour and manifests in the compound PbCuTe
2
O
6
. Using a combination of experiment and theory, we show that this system exhibits signs of being a quantum spin liquid with no detectable static magnetism together with the presence of diffuse continua in the magnetic spectrum suggestive of fractional spinon excitations.
Metal oxide nanoparticles synthesized by the biological method represent the most recent research in nanotechnology. This study reports the rapid and ecofriendly approach for the synthesis of CeO2 ...nanoparticles mediated using the Abelmoschus esculentus extract. The medicinal plant extract acts as both a reducing and stabilizing agent. The characterization of CeO2 NPs was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared spectroscopy (FTIR). The in vitro cytotoxicity of green synthesized CeO2 was assessed against cervical cancerous cells (HeLa). The exposure of CeO2 to HeLa cells at 10–125 µg/mL caused a loss in cellular viability against cervical cancerous cells in a dose-dependent manner. The antibacterial activity of the CeO2 was assessed against S. aureus and K. pneumonia. A significant improvement in wound-healing progression was observed when cerium oxide nanoparticles were incorporated into the chitosan hydrogel membrane as a wound dressing.
Renormalization group methods are well-established tools for the (numerical) investigation of the low-energy properties of correlated quantum many-body systems, allowing us to capture their ...scale-dependent nature. The functional renormalization group (FRG) allows us to continuously evolve a microscopic model action to an effective low-energy action as a function of decreasing energy scales via an exact functional flow equation, which is then approximated by some truncation scheme to facilitate computation. Here, we report on our implementation of multiloop FRG, an extended truncation scheme recently developed for electronic FRG calculations, within the pseudofermion functional renormalization group (pf-FRG) framework for interacting quantum spin systems. We discuss in detail the conceptual intricacies of the flow equations generated by the multiloop truncation, as well as essential refinements to the integration scheme for the resulting integrodifferential equations. To benchmark our approach, we analyze antiferromagnetic Heisenberg models on the pyrochlore, simple cubic, and face-centered cubic lattice, discussing the convergence of physical observables for higher-loop calculations and comparing with existing results where available. Combined, these methodological refinements systematically improve the pf-FRG approach to one of the numerical tools of choice when exploring frustrated quantum magnetism in higher spatial dimensions.
We present a detailed study of the ground-state phase diagram of the classical frustrated Heisenberg model on the face-centered-cubic lattice. By considering exchange interactions to third nearest ...neighbors, we find commensurate, helimagnetic, as well as noncollinear, multi-Q orders which include noncoplanar and chiral spin structures. We reveal the presence of subextensively degenerate manifolds that appear at triple points and certain phase boundaries in the phase diagram. Within these manifolds, the spin Hamiltonian can be recast as a complete square of spins on finite motifs, permitting us to identify families of exact ground-state spin configurations in real space—these include randomly stacked ferro- or antiferromagnetically ordered planes and interacting ferromagnetic chains, among others. Finally, we critically investigate the ramifications of our findings on the example of the Ising model, where we exactly enumerate all the states numerically for finite clusters.
We investigate the quantum Heisenberg model on the pyrochlore lattice for a generic spinSin the presence of nearest-neighborJ1and second-nearest-neighborJ2exchange interactions. By employing the ...pseudofermion functional renormalization group method, we find, forS=1/2andS=1, an extended quantum-spin-liquid phase centered aroundJ2=0, which is shown to be robust against the introduction of breathing anisotropy. The effects of temperature, quantum fluctuations, breathing anisotropies, and aJ2coupling on the nature of the scattering profile, and the pinch points, in particular, are studied. For the magnetic phases of theJ1−J2model, quantum fluctuations are shown to renormalize phase boundaries compared to the classical model and to modify the ordering wave vectors of spiral magnetic states, while no new magnetic orders are stabilized.
The breeding for varieties tolerant of adverse growing conditions is critical for sustainable agriculture, especially for ramie (
L.). However, a lack of information on the tolerance of ramie to ...nutrient-deficient conditions has hindered efforts to breed ramie varieties tolerant of such conditions. The main objective of this study was to explore the tolerance strategies of ramie plants under poor soil conditions using long-term (8-9 years) field trials. Genotypes of Duobeiti 1 and Xiangzhu XB were highly tolerant of poor soil conditions. The contributions of seasonal nutrient cycling and rhizobacteria to the ability of ramie to tolerate poor soil were tested. Nitrogen and phosphorus retranslocation to the root at the end of the growing season helped ramie adapt to poor soil conditions. The contribution of the microbial community was analyzed using high-throughput Illumina MiSeq sequencing technology. The enrichment of beneficial bacteria (mainly
,
, and
) and the reduction of harmful fungi (mainly
and
) also contributed to the ability of ramie to tolerate poor soils. The results of this study provide new insight into the ability of ramie to tolerate adverse conditions and aid future efforts to breed and cultivate ramie tolerant of adverse conditions.
Abstract
We address the long-standing problem of the microscopic origin of the richly diverse phenomena in the chromium breathing pyrochlore material family. Combining electronic structure and ...renormalization group techniques we resolve the magnetic interactions and analyze their reciprocal-space susceptibility. We show that the physics of these materials is principally governed by long-range Heisenberg Hamiltonian interactions, a hitherto unappreciated fact. Our calculations uncover that in these isostructural compounds, the choice of chalcogen triggers a proximity of the materials to classical spin liquids featuring degenerate manifolds of wave-vectors of different dimensions: A Coulomb phase with three-dimensional degeneracy for LiInCr
4
O
8
and LiGaCr
4
O
8
, a spiral spin liquid with two-dimensional degeneracy for CuInCr
4
Se
8
and one-dimensional line degeneracies characteristic of the face-centered cubic antiferromagnet for LiInCr
4
S
8
, LiGaCr
4
S
8
, and CuInCr
4
S
8
. The surprisingly complex array of prototypical pyrochlore behaviors we discovered in chromium spinels may inspire studies of transition paths between different semi-classical spin liquids by doping or pressure.
Miscanthus, which is a leading dedicated-energy grass in Europe and in parts of Asia, is expected to play a key role in the development of the future bioeconomy. However, due to its complex genetic ...background, it is difficult to investigate phylogenetic relationships in this genus. Here, we investigated 50 Miscanthus germplasms: 1 female parent (M. lutarioriparius), 30 candidate male parents (M. lutarioriparius, M. sinensis, and M. sacchariflorus), and 19 offspring. We used high-throughput Specific-Locus Amplified Fragment sequencing (SLAF-seq) to identify informative single nucleotide polymorphisms (SNPs) in all germplasms.
We identified 257,889 SLAF tags, of which 87,162 were polymorphic. Each tag was 264-364 bp long. The obtained 724,773 population SNPs were used to investigate genetic relationships within three species of Miscanthus. We constructed a phylogenetic tree of the 50 germplasms using the obtained SNPs and grouped them into two clades: one clade comprised of M. sinensis alone and the other one included the offspring, M. lutarioriparius, and M. sacchariflorus. Genetic cluster analysis had revealed that M. lutarioriparius germplasm C3 was the most likely male parent of the offspring.
As a high-throughput sequencing method, SLAF-seq can be used to identify informative SNPs in Miscanthus germplasms and to rapidly characterize genetic relationships within this genus. Our results will support the development of breeding programs with the focus on utilizing Miscanthus cultivars with elite biomass- or fiber-production potential for the developing bioeconomy.
Motivated by recent experiments on Cs
_2
2
Cu
_3
3
SnF
_{12}
12
and YCu
_{3}
3
(OH)
_{6}
6
Cl
_{3}
3
,
we consider the
{S=1/2}
S
=
1
/
2
Heisenberg model on the kagome lattice with nearest-neighbor
...super-exchange
J
J
and (out-of-plane) Dzyaloshinskii-Moriya interaction
J_D
J
D
,
which favors (in-plane)
{Q=(0,0)}
Q
=
(
0
,
0
)
magnetic order. By using both variational Monte Carlo and tensor-network
approaches, we show that the ground state develops a finite
magnetization for
J_D/J \gtrsim 0.03 \mathrm{-} 0.04
J
D
/
J
≳
0.03
−
0.04
;
instead, for smaller values of the Dzyaloshinskii-Moriya interaction,
the ground state has no magnetic order and, according to the fermionic
wave function, develops a gap in the spinon spectrum, which vanishes for
J_D \to 0
J
D
→
0
.
The small value of
J_D/J
J
D
/
J
for the onset of magnetic order is particularly relevant for the
interpretation of low-temperature behaviors of kagome antiferromagnets,
including ZnCu
_{3}
3
(OH)
_{6}
6
Cl
_{2}
2
.
For this reason, we assess the spin dynamical structure factor and the
corresponding low-energy spectrum, by using the variational Monte Carlo
technique. The existence of a continuum of excitations above the magnon
modes is observed within the magnetically ordered phase, with a broad
peak above the lowest-energy magnons, similarly to what has been
detected by inelastic neutron scattering on
Cs
_{2}
2
Cu
_{3}
3
SnF
_{12}
12
.
Globally, the surge in disease and urgency in maintaining social distancing has reawakened the use of telemedicine/telehealth. Amid the global health crisis, the world adopted the culture of online ...consultancy. Thus, there is a need to revamp the conventional model of the telemedicine system as per the current challenges and requirements. Security and privacy of data are main aspects to be considered in this era. Data-driven organizations also require compliance with regulatory bodies, such as HIPAA, PHI, and GDPR. These regulatory compliance bodies must ensure user data privacy by implementing necessary security measures. Patients and doctors are now connected to the cloud to access medical records, e.g., voice recordings of clinical sessions. Voice data reside in the cloud and can be compromised. While searching voice data, a patient’s critical data can be leaked, exposed to cloud service providers, and spoofed by hackers. Secure, searchable encryption is a requirement for telemedicine systems for secure voice and phoneme searching. This research proposes the secure searching of phonemes from audio recordings using fully homomorphic encryption over the cloud. It utilizes IBM’s homomorphic encryption library (HElib) and achieves indistinguishability. Testing and implementation were done on audio datasets of different sizes while varying the security parameters. The analysis includes a thorough security analysis along with leakage profiling. The proposed scheme achieved higher levels of security and privacy, especially when the security parameters increased. However, in use cases where higher levels of security were not desirous, one may rely on a reduction in the security parameters.
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