arXiv subjects

Shinichiro Nakamura

Publications and source records attributed to Shinichiro Nakamura.

4 recordsLinked to original sources

arXiv2026

Weakly spin-dependent band structures of antiferromagnetic perovskite LaMO$_3$ (M = Cr, Mn, Fe)

We investigate spin-dependent electronic states of antiferromagnetic (AFM) lanthanum chromite (LaCrO$_3$), lanthanum manganite (LaMnO$_3$), and lanthanum ferrite (LaFeO$_3$) using spin-polarized first-principles density functional theory (DFT) with Hubbard U correction. The band structures are calculated for 15 types of their different AFM structures. It is verified for these structures that there is a very simple rule to identify which wave number k exhibits spin splitting or degeneracy in the band structure. This rule uses the symmetry operations that map the up-spin atoms onto the down-spin atoms. The resulting spin splitting is very small for the most stable spin configuration of the most stable experimental structure. We discuss a plausible benefit of this characteristic, i.e., the direction-independence of the spin current, in electrode applications.

cond-mat.mtrl-sci↗

arXiv2025

Motional representation; the ability to predict odor characters using molecular vibrations

The prediction of odor characters is still impossible based on the odorant molecular structure. We designed a CNN-based regressor for computed parameters in molecular vibrations (CNN\_vib), in order to investigate the ability to predict odor characters of molecular vibrations. In this study, we explored following three approaches for the predictability; (i) CNN with molecular vibrational parameters, (ii) logistic regression based on vibrational spectra, and (iii) logistic regression with molecular fingerprint(FP). Our investigation demonstrates that both (i) and (ii) provide predictablity, and also that the vibrations as an explanatory variable (i and ii) and logistic regression with fingerprints (iii) show nearly identical tendencies. The predictabilities of (i) and (ii), depending on odor descriptors, are comparable to those of (iii). Our research shows that odor is predictable by odorant molecular vibration as well as their shapes alone. Our findings provide insight into the representation of molecular motional features beyond molecular structures.

physics.chem-ph↗

arXiv2024

A simple DNN regression for the chemical composition in essential oil

Although experimental design and methodological surveys for mono-molecular activity/property has been extensively investigated, those for chemical composition have received little attention, with the exception of a few prior studies. In this study, we configured three simple DNN regressors to predict essential oil property based on chemical composition. Despite showing overfitting due to the small size of dataset, all models were trained effectively in this study.

cs.LG↗

arXiv2018

Superconductivity in BaPtSb with an Ordered Honeycomb Network

Superconductivity in BaPtSb with the SrPtSb-type structure (space group $P\bar{6}m2$, $D_{3h}^1$, No. 187) is reported. The structure consists of a PtSb ordered honeycomb network that stacks along the $c$-axis so that spatial inversion symmetry is broken globally. Electrical resistivity and specific-heat measurements revealed that the compound exhibited superconductivity at 1.64 K. The noncentrosymmetric structure and the strong spin-orbit coupling of Pt and Sb make BaPtSb an attractive compound for studying the exotic superconductivity predicted for a honeycomb network.

cond-mat.supr-con↗