New magnetic intermediate state, "B - phase, " in the cubic chiral magnet MnSi

It is well known that the archetype chiral magnet MnSi stabilizes a skyrmion lattice, termed "A-phase, "in a narrow temperature range in the vicinity of the paramagnetic boundary around Tc ~29 K and Hc ~2 kOe. Recently, it has been predicted that at much lower temperatures below Tc, the conical helicoid and the forced ferromagnetic (FFM) states could be separated by a new "unknown state."In order to detect this "unknown state, "we explored the phase diagram of MnSi oriented single crystals as a function of the d.c. magnetic field (H - dc) and the temperature (T) by using a.c. magnetization measurements. For H - dc¿ , we observed a new region, termed "B-phase, "in the magnetic phase diagram, characterized by a flat-valley-like anomaly on the in-phase component of the a.c. magnetization (m'), over 3.5 = Hdc = 6.2 kOe just below the low temperature (T or , revealing that the magnetic anisotropy could play a role in the stabilization of the phase. The "B-phase"could be compatible with the theoretical predictions if the new magnetic state is supposedly related with a relative reorientation of the four helices in MnSi

New magnetic intermediate state, "B - phase," in the cubic chiral magnet MnSi

It is well known that the archetype chiral magnet MnSi stabilizes a skyrmion lattice, termed “A-phase,” in a narrow temperature range in the vicinity of the paramagnetic boundary around Tc ∼ 29 K and Hc ∼ 2 kOe. Recently, it has been predicted that at much lower temperatures below Tc, the conical helicoid and the forced ferromagnetic (FFM) states could be separated by a new “unknown state.” In order to detect this “unknown state,” we explored the phase diagram of MnSi oriented single crystals as a function of the d.c. magnetic field (⃗ dc) and the temperature (T) by using a.c. magnetization measurements. For ⃗ dc∥∥ 〈111〉, we observed a new region, termed “B-phase,” in the magnetic phase diagram, characterized by a flat-valley-like anomaly on the in-phase component of the a.c. magnetization (m′), over 3.5 ≤ Hdc ≤ 6.2 kOe just below the low temperature (T < 6 K) FFM boundary. The observed frequency independence over 0.3–1000 Hz and the absence of any measurable absorption in the a.c. magnetization (m″) in the “B-phase” suggest a static nature. The “B-phase” was not observed for either ⃗ dc∥∥ 〈100〉 or 〈110〉, revealing that the magnetic anisotropy could play a role in the stabilization of the phase. The “B-phase” could be compatible with the theoretical predictions if the new magnetic state is supposedly related with a relative reorientation of the four helices in MnSi.This work was funded by MCIN/AEI/10.13039/501100011033 under Grant No. PGC2018099024B100. Grant No. OTR02223 from CSIC/MICIN and Grant No. DGA/M4 from Diputación General de Aragón (Spain) are also acknowledged. This work was supported by Grants-in-Aid for Scientific Research, Grant No. (S) 25220803, from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; by JSPS KAKENHI under Grant Nos. K16KK0102, H17H06137, K19KK0070, and H20H02642; by the MEXT program for promoting the enhancement of research universities; by the JSPS Core-to-Core Program, A. (Advanced Research Networks); and by the Chirality Research Center (Crescent) in Hiroshima University.Peer reviewe

Circulating Malondialdehyde-Modified LDL-Related Variables and Coronary Artery Stenosis in Asymptomatic Patients with Type 2 Diabetes

Aims. To elucidate the levels of malondialdehyde-modified LDL (MDA-LDL)-related variables for predicting coronary artery stenosis (CAS) by coronary CT angiography (CCTA) in asymptomatic patients with type 2 diabetes (T2DM). Methods. Enrolled were 36 Japanese patients with T2DM who underwent CCTA and in whom MDA-LDL levels were measured. Definition of CAS was luminal narrowing of ≥50%. Trends through tertiles of each MDA-LDL-related variable were analyzed with a general linear model. The ability of each MDA-LDL-related variable to predict CAS was compared to areas under the curve (AUCs) in receiver operating characteristic curve (ROC) analysis. Results. Seventeen patients had CAS. Each MDA-LDL-related variable was an independent predictor of CAS (P=0.039 for MDALDL, P=0.013 for MDA-LDL/LDL-C, P=0.047 for MDA-LDL/HDL-C, and P=0.013 for (MDA-LDL/LDL-C)/HDL-C). AUCs of MDA-LDL, MDA-LDL/LDL-C, MDA-LDL/HDL-C, and (MDA-LDL/LDL-C)/HDL-C were 0.675 (95% CI 0.496–0.854), 0.765 (0.602–0.927), 0.752 (0.592–0.913), and 0.799 (0.643–0.955), respectively, for predicting CAS. Trends throughout the tertiles showed significant associations between MDA-LDL/LDL-C, MDA-LDL/HDL-C, or (MDALDL/LDL-C)/HDL-C and CAS (P=0.003 for MDA-LDL/LDL-C, P=0.042 for MDA-LDL/HDL-C, and P=0.001 for (MDA-LDL/LDL-C)/HDL-C). Conclusions. Data suggest that measurements of MDA-LDL/LDL-C, MDA-LDL/HDLC, and (MDA-LDL/LDL-C)/HDL-C are useful for predicting CAS