Predominance of the Kitaev interaction in a three-dimensional honeycomb iridate: from ab-initio to spin model

The recently discovered three-dimensional hyperhoneycomb iridate, $\beta$-Li$_2$IrO$_3$, has raised hopes for the realization of dominant Kitaev interaction between spin-orbit entangled local moments due to its near-ideal lattice structure. If true, this material may lie close to the sought-after quantum spin liquid phase in three dimensions. Utilizing ab-initio electronic structure calculations, we first show that the spin-orbit entangled basis, $j_{\rm eff}$=1/2, correctly captures the low energy electronic structure. The effective spin model derived in the strong coupling limit supplemented by the ab-initio results is shown to be dominated by the Kitaev interaction. We demonstrated that the possible range of parameters is consistent with a non-coplanar spiral magnetic order found in a recent experiment. All of these analyses suggest that $\beta$-Li$_2$IrO$_3$ may be the closest among known materials to the Kitaev spin liquid regime.Comment: 9 pages, 6 figures, 2 table

Green Bitcoin: Global Sound Money

Modern societies have adopted government-issued fiat currencies many of which exist today mainly in the form of digits in credit and bank accounts. Fiat currencies are controlled by central banks for economic stimulation and stabilization. Boom-and-bust cycles are created. The volatility of the cycle has become increasingly extreme. Social inequality due to the concentration of wealth is prevalent worldwide. As such, restoring sound money, which provides stored value over time, has become a pressing issue. Currently, cryptocurrencies such as Bitcoin are in their infancy and may someday qualify as sound money. Bitcoin today is considered as a digital asset for storing value. But Bitcoin has problems. The first issue of the current Bitcoin network is its high energy consumption consensus mechanism. The second is the cryptographic primitives which are unsafe against post-quantum (PQ) attacks. We aim to propose Green Bitcoin which addresses both issues. To save energy in consensus mechanism, we introduce a post-quantum secure (self-election) verifiable coin-toss function and novel PQ secure proof-of-computation primitives. It is expected to reduce the rate of energy consumption more than 90 percent of the current Bitcoin network. The elliptic curve cryptography will be replaced with PQ-safe versions. The Green Bitcoin protocol will help Bitcoin evolve into a post-quantum secure network.Comment: 16 page

Emergence of flat bands via orbital-selective electron correlations in Mn-based kagome metal

Kagome lattice has been actively studied for the possible realization of frustration-induced two-dimensional flat bands and a number of correlation-induced phases. Currently, the search for kagome systems with a nearly dispersionless flat band close to the Fermi level is ongoing. Here, by combining theoretical and experimental tools, we present Sc$_3$Mn$_3$Al$_7$Si$_5$ as a novel realization of correlation-induced almost-flat bands in the kagome lattice in the vicinity of the Fermi level. Our magnetic susceptibility, $^{27}$Al nuclear magnetic resonance, transport, and optical conductivity measurements provide signatures of a correlated metallic phase with tantalizing ferromagnetic instability. Our dynamical mean-field calculations suggest that such ferromagnetic instability observed originates from the formation of nearly flat dispersions close to the Fermi level, where electron correlations induce strong orbital-selective renormalization and manifestation of the kagome-frustrated bands. In addition, a significant negative magnetoresistance signal is observed, which can be attributed to the suppression of flat-band-induced ferromagnetic fluctuation, which further supports the formation of flat bands in this compound. These findings broaden a new prospect to harness correlated topological phases via multiorbital correlations in 3$d$-based kagome systems.Comment: 16 pages, 15 figure

Erratum: Nation-Wide Korean Breast Cancer Data from 2008 Using the Breast Cancer Registration Program

nation-wide breast cancer data and analyzed the data using their online registration program biannually. The purpose of this study was to evaluate the characteristics of Korean breast cancer from 2008 and examine chronological based patterns. Methods: Data were collected from 38 medical schools (67 hospitals), 20 general hospitals, and 10 private clinics. The data on the total number, gender, and age distribution were collected through a questionnaire as well as other detailed data analyzed via the online registration program. Results: In 2008, there were 13,908 patients who were newly diagnosed with breast cancer. The crude incidence rate of female breast cancer was 57.3 among 100,000 and the median age was 49 years. The age distribution had not changed since the initial survey; however the proportion of postmenopausal patients had increased and median age was older than the past. In staging distribution, the proportion of early breast cancer (stage 0, I) was 47.2 % with, breast-conserving surgery performed in 58 % and mastectomy in 39.5%. Conclusion: Compared to past data, the incidence of breast cancer in Korea continues to rise. Furthermore, the proportion of those detected by screening and breast conservation surgery has increased remarkably. To understand the patterns of Korean breast cancer, the nation-wide data should continuously investigated

Topological and magnetic phases with strong spin-orbit coupling on the hyperhoneycomb lattice

We study the general phase diagram of correlated electrons for iridium-based (Ir) compounds on the hyperhoneycomb lattice, a crystal structure where the Ir4+ ions form a three-dimensional network with threefold coordination recently realized in the beta-Li2IrO3 compound. Using a combination of microscopic derivations, symmetry analysis, and density functional calculations, we determine the general model for the electrons occupying the j(eff) = 1/2 orbitals at the Ir4+ sites. In the noninteracting limit, we find that this model allows for both topological and trivial electronic band insulators along with metallic states. The effect of Hubbard-type electron-electron repulsion on the above electronic structure in stabilizing q = 0 magnetic order reveals a phase diagram with continuous phase transition between a topological band insulator and a Neel ordered magnetic insulator.close3

A Herbal Medicine, Gongjindan

This study protocol aims to explore the effectiveness, safety, and cost-effectiveness of a herbal medication, Gongjindan (GJD), in patients with chronic dizziness. This will be a prospective, multicenter, randomized, double-blind, placebo-controlled, parallel-group, clinical trial. Seventy-eight patients diagnosed with Meniere’s disease, psychogenic dizziness, or dizziness of unknown cause will be randomized and allocated to either a GJD or a placebo group in a 1 : 1 ratio. Participants will be orally given 3.75 g GJD or placebo in pill form once a day for 56 days. The primary outcome measure will be the Dizziness Handicap Inventory score. Secondary outcome measures will be as follows: severity (mean vertigo scale and visual analogue scale) and frequency of dizziness, balance function (Berg Balance Scale), fatigue (Fatigue Severity Scale) and deficiency pattern/syndrome (qi blood yin yang-deficiency questionnaire) levels, and depression (Korean version of Beck’s Depression Inventory) and anxiety (State-Trait Anxiety Inventory) levels. To assess safety, adverse events, including laboratory test results, will be monitored. Further, the incremental cost-effectiveness ratio will be calculated based on quality-adjusted life years (from the EuroQoL five dimensions’ questionnaire) and medical expenses. Data will be statistically analyzed at a significance level of 0.05 (two-sided). This trial is registered with ClinicalTrials.gov NCT03219515, in July 2017