Exact diagonalization and cluster mean-field study of triangular-lattice XXZ antiferromagnets near saturation

Quantum magnetic phases near the magnetic saturation of triangular-lattice antiferromagnets with XXZ anisotropy have been attracting renewed interest since it has been suggested that a nontrivial coplanar phase, called the $\pi$-coplanar or $\Psi$ phase, could be stabilized by quantum effects in a certain range of anisotropy parameter $J/J_z$ besides the well-known 0-coplanar (known also as $V$) and umbrella phases. Recently, Sellmann $et$ $al$. [Phys. Rev. B {\bf 91}, 081104(R) (2015)] claimed that the $\pi$-coplanar phase is absent for $S=1/2$ from an exact-diagonalization analysis in the sector of the Hilbert space with only three down-spins (three magnons). We first reconsider and improve this analysis by taking into account several low-lying eigenvalues and the associated eigenstates as a function of $J/J_z$ and by sensibly increasing the system sizes (up to 1296 spins). A careful identification analysis shows that the lowest eigenstate is a chirally antisymmetric combination of finite-size umbrella states for $J/J_z\gtrsim 2.218$ while it corresponds to a coplanar phase for $J/J_z\lesssim 2.218$. However, we demonstrate that the distinction between 0-coplanar and $\pi$-coplanar phases in the latter region is fundamentally impossible from the symmetry-preserving finite-size calculations with fixed magnon number.} Therefore, we also perform a cluster mean-field plus scaling analysis for small spins $S\leq 3/2$. The obtained results, together with the previous large-$S$ analysis, indicate that the $\pi$-coplanar phase exists for any $S$ except for the classical limit ($S\rightarrow \infty$) and the existence range in $J/J_z$ is largest in the most quantum case of $S=1/2$.Comment: 13 pages, 13 figure

Consumer Inventory and the Cost of Living Index : Theory and Some Evidence from Japan

This paper examines the implications of consumer inventory for cost-of-living indices (COLIs) and business cycles. We begin by providing stylized facts about consumer inventory using scanner data. We then construct a quasi-dynamic model to describe consumers\u27 purchase, consumption, and inventory behavior. A key feature of our model is that inventory is held by household producers, not by consumers, which enables us to construct a COLI in a static manner even in an economy with storable goods. Based on this model, we show that stockpiling during temporary sales generates a substantial bias, or so-called chain drift, in conventional price indices, which are constructed without paying attention to consumer inventory. However, the chain drift is greatly mitigated in our COLI, which is based on consumption prices (rather than purchase prices) and quantities consumed (rather than quantities purchased). We provide empirical evidence supporting these theoretical predictions. We also show empirically that consumers\u27 inventory behavior tends to depend on labor market conditions and the interest rate.Publisher\u27s another name: JSPS Grants-in-Aid for Scientific Research (S) Central Bank Communication DesignJEL classication number : C43, D15, E3

Dilute-Bose-Gas Approach to ground state phases of 3D quantum helimagnets under high magnetic field

We study high-field phase diagram and low-energy excitations of three-dimensional quantum helimagnets. Slightly below the saturation field, the emergence of magnetic order may be mathematically viewed as Bose-Einstein condensation (BEC) of magnons. The method of dilute Bose gas enables an unbiased quantitative analysis of quantum effects in three-dimensional helimagnets and thereby three phases are found: cone, coplanar fan and an attraction-dominant one. To investigate the last phase, we extend the usual BEC approach so that we can handle 2-magnon bound states. In the case of 2-magnon BEC, the transverse magnetization vanishes and long-range order occurs in the quadrupolar channel (spin-nematic phase). As an application, we map out the phase diagram of a 3D helimagnet which consists of frustrated J1-J2 chains coupled by an interchain interaction J3.Comment: 4pages, 3figures, International Conference on Magnetism (ICM) 2009 (Karlsruhe, Germany, July 26-31, 2009)

Examination of Wireless Power Transfer Combined With the Utilization of Distance Detection

Wireless power transfer using magnetic resonant coupling is expected to be widely used in the charging of an electric vehicle and in the use of home electric appliances. Wireless power transfer requires a high efficiency and power transfer over a long distance. However, the efficiency is reduced by the increase of the transmission distance and the change of the impedance of the receiving load. Therefore, a distance sensor using magnetic resonant coupling is proposed. In this paper, we propose a method of power transfer and distance detection using one couple of coils in real time. We also propose to use different frequencies in the power transfer and the distance detection, which are superposed and separated. Using the proposed approach, we demonstrated that the power transfer and the distance detection can be performed without relying on the change of the transmission distance.ArticleIEEE TRANSACTIONS ON MAGNETICS. 50(11):4005304 (2014)journal articl

Initiatives of the Hiroshima University Writing Center Expanding and Developing University Library Functions

広島大学ライティングセンターは学習支援と研究支援を行うことを目的として設置され，広島大学図書館はライティングセンターの設置と運営に中心的な役割を果たしている。ライティングセンターは学習支援としてライティング相談を，研究支援として研究成果発信のための様々な取り組みを行い，学習と研究の両面のサポートを行っている。ライティングセンターが行っている活動は，図書館が他の関連部署と密接に連携し，学習と研究の両面からアカデミックライティングの支援を行うことで，大学図書館機能を拡張し，発展させていく先駆的な取り組みである。 The Hiroshima University Writing Center was established with the goal of supporting learning and research, and the Hiroshima University Library plays a central role in the Writing Centerʼs establishment and operation. TheWriting Center engages in a variety of support initiatives for both learning and research, offering writing consultation for the former and submission of research findings for the latter. The library closely coordinates the Writing Centerʼs activities with other related departments, and through academic writing support for both learning and research, these trailblazing efforts expand and develop the university libraryʼs functions

Regional microclimate humidity of clothing during light work as a result of the interaction between local sweat production and ventilation

Purpose – The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work-shirts immediately after the onset of sweating in light exercise. Design/methodology/approach – The clothing microclimate ventilations were measured at chest, back and upper arm using a manikin. Separate wear trials were performed to determine the sweat production and the humidity of the clothing microclimate at the same locations as where the ventilation was measured during light exercise. Findings – Every shirt shows the greatest value of ventilation index (VI) for the chest and the smallest one for the upper arm. The values of VI differ remarkably at the chest among the five shirts. Comfort sensation became gradually worse as the time passed after starting exercise. There was no significant difference among the clothing conditions in mean values of rectal temperature, local skin temperatures, microclimate temperatures, microclimate relative humidities and local sweat rates at three regions over 10?min after the onset of sweating. A relationship was observed between the ratio of the mean moisture concentration in the clothing microclimate to the mean sweat rate at the chest and the back and the VI. Originality/value – The results suggest that clothing ventilation should be measured in different body regions in response to sweat rates in corresponding regions

Baseline Neutrophil-to-Lymphocyte Ratio and Glasgow Prognostic Score are Associated with Clinical Outcome in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma Treated with Nivolumab

Recurrent or metastatic head and neck squamous cell carcinoma (R/MHNSCC) has a poor prognosis. Although nivolumab is approved in Japan for treating R/MHNSCC, the response rate is low. Therefore, identifying pretreatment prognostic factors is necessary. This study assessed the utility of the neutrophil-to-lymphocyte ratio (NLR) and Glasgow Prognostic Score (GPS) as biomarkers of response to nivolumab. We retrospectively collected the data of 56 R/MHNSCC patients treated with nivolumab between May 2017 and December 2019. The Kaplan–Meier method and log-rank test were used to estimate overall survival (OS) and progression-free survival (PFS), and multivariate Cox hazard regression analysis was used to identify independent predictors of survival. Patients with a low pretreatment NLR had prolonged OS, and patients with a low pretreatment GPS had increased OS and PFS. A performance score (PS) of 0-1, development of immune-related adverse events, and GPS of 0-1 were significantly associated with OS in multivariate analysis. In summary, baseline pretreatment NLR and GPS are independently associated with OS in R/MHNSCC patients treated with nivolumab. Administration of nivolumab while maintaining the PS reflects a immune status of the host and leads to a good OS