47 research outputs found
Emergent cross-product-type spin-orbit coupling under ferroaxial ordering
No full textA ferroic alignment of a time-reversal-even axial vector, which is called the ferroaxial ordered state, is identified by the spontaneous rotational distortion of the lattice structure to break vertical mirror symmetry. We theoretically investigate what happens in the electronic structure once ferroaxial ordering occurs by analyzing a tetragonal d-p cluster model with transition metal oxide in mind. By adopting the symmetry-adapted multipole representation, we elucidate the emergent cross-product form of the spin-orbit coupling by the interplay between the atomic spin-orbit coupling and the d-p hybridization according to vertical mirror symmetry breaking, which corresponds to the electronic order parameter of ferroaxial ordering
日本産あかねの色素
No full textThe pigment of "akane" was first investigated by H. KONDO, and next by S. WADA. KONDO reported purpurin as a main pigment, but WADA contended that it is only pseudpurpurin that naturally exists, and purpurin, found by KONDO, must be derived from pseud-purpurin. In the author's expements, two crystalline pigments were isolated from "akane"; one was purpurin and the other might be pseud-purpurin found by WADA. The author showed these two pigments are contained in "akane" as natural constituents
Magnetic instability under ferroaxial moment
No full textMagnetic anisotropy is one of the important factors in determining magnetic structures. The type of magnetic anisotropy is closely related to the symmetry of crystals. We theoretically investigate magnetic anisotropy and its related magnetic instability arising from an electric axial moment, which appears under the breaking of the mirror symmetry parallel to the moment but does not require the breakings of both spatial inversion and time-reversal symmetries. By performing perturbation and mean-field calculations in a complementary way, we show the appearance of the in-plane magnetic anisotropy when the electric axial moment occurs, which tends to tilt in-plane spin moments from the crystal axes in collaboration with relativistic spin-orbit coupling. We demonstrate such a tendency for single-sublattice and four-site cluster models. In the four-site cluster model, we show that a spin configuration consisting of magnetic monopole and magnetic toroidal dipole tends to be realized in the region where a spin vortex is stabilized by the exchange interactions
Un écrivain mouvementé ; Ferrier’s dynamic style and identity
No full textThe BRAKC research centre hosts an afternoon of talks and discussion, with Michaël Ferrier, the acclaimed French writer, who will be visiting us from Tokyo where he lives.
Based loosely on the author’s life, Mémoires d’outre-mer recounts the life of Ferrier’s Mauritius-born grandfather, Maxime, who in 1922 abruptly boarded a boat bound for Madagascar and never returned. Maxime’s adventurous and romantic life in Madagascar, which included a stint as a diver, an artist, and an acrobat in a travelling circus, is bound up with the island’s history, including its period as a Vichy-governed territory at the centre of what was called ‘Project Madagascar’, the Nazi plan to relocate Europe’s Jewish population to the island. This story in turn is interwoven with the larger story of colonialism and its lasting and complicated impact on French national and cultural identity today.
Join us at Birkbeck on 18th September 2019 for a discussion of this novel and its translation, as well as of Ferrier’s other works. The event is free but please book as places are limited.
Michaël Ferrier is professor of French at Chuo University in Tokyo, Japan; he is also an essayist and the award-winning author of several novels. Mémoires d’outre-mer, his most recent work, has been translated into English as Over Seas of Memory by Martin Munro , Winthrop-King professor of French and Francophone Studies at Florida State University.
This event is organised by Dr Akane Kawakami, who is Head of the Department of Cultures and Languages at Birkbeck, and by the BRAKC research centre (Birkbeck Research in Aesthetics of Kinship and Community)
Magnetic instability under ferroaxial moment
No full textMagnetic anisotropy is one of the important factors in determining magnetic structures. The type of magnetic anisotropy is closely related to the symmetry of crystals. We theoretically investigate magnetic anisotropy and its related magnetic instability arising from an electric axial moment, which appears under the breaking of the mirror symmetry parallel to the moment but does not require the breakings of both spatial inversion and time-reversal symmetries. By performing perturbation and mean-field calculations in a complementary way, we show the appearance of the in-plane magnetic anisotropy when the electric axial moment occurs, which tends to tilt in-plane spin moments from the crystal axes in collaboration with relativistic spin-orbit coupling. We demonstrate such a tendency for single-sublattice and four-site cluster models. In the four-site cluster model, we show that a spin configuration consisting of magnetic monopole and magnetic toroidal dipole tends to be realized in the region where a spin vortex is stabilized by the exchange interactions
Nonlinear Transverse Magnetic Susceptibility under Electric Toroidal Dipole Ordering
No full textAn electric toroidal dipole (ETD) moment is one of the fundamental dipole
moments as well as electric and magnetic ones. Although it directly couples to
neither an electric nor magnetic field due to its spatial inversion and
time-reversal parities, its ordered state leads to unconventional transverse
responses of the conjugate physical quantities. We here theoretically
investigate nonlinear transverse magnetic susceptibility under the ETD
ordering. By performing a self-consistent mean-field calculation for a five
-orbital model under a tetragonal crystalline electric field and using the
nonlinear Kubo formula, we show that a third-order transverse magnetic
susceptibility corresponding to a uniform magnetization perpendicular to the
external magnetic field becomes nonzero once the ETD moment is ordered.
Moreover, we find that spin-orbital entanglement and a low-lying first excited
crystal-field level are important for realizing large transverse responses.Comment: 5 pages with 4 figure
正倉院の赤系統染色裂の染料に関する研究
No full textNo chemical method has ever been used in studies on the dyestuffs of ancient textiles. In present studies, the author applied chemical techniques in the investigation on fragments of the red-coloured textiles in the Shōsōin, and, from these textiles, isolated two crystalline pigments, one of which was identified with purpurin, and the other was munjistin. As shown in the former work, these two anthraquinoid pigments are present in the root of "Akane" (Rubia cordifolia var. munjista), the author concluded that those ancient red-coloured textiles were dyed with the root of "Akane"
Lipase‐Palladium Co‐catalyzed Dynamic Kinetic Resolution of Racemic Allylic Esters
No full textThis is the accepted version of the following article: Oono Masato, Yamada Akane, Kimura Masanari, et al. Lipase‐Palladium Co‐catalyzed Dynamic Kinetic Resolution of Racemic Allylic Esters. Chemistry – A European Journal, e202404406, which has been published in final form at https://doi.org/10.1002/chem.202404406. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html]Dynamic kinetic resolution (DKR) by combining lipase-catalyzed esterification of racemic sec-alcohols and in situ racemization has been widely studied; however, reports on DKR involving lipase-catalyzed hydrolysis of racemic esters are scarce. This problem is probably due to the lack of more effective and general racemization methods. Herein, we report the enhanced hydrolytic DKR of racemic allylic esters. The discovery of the monodentate ligand P[C6H3-2,6-(OMe)2]3, which in situ generates Pd complex(es) highly reactive to racemization and the NaOAc-mediated acceleration of racemization, are notable breakthroughs. Consequently, the DKR of racemic allylic esters can be completed in a few hours at 40 °C in most cases, yielding optically active allylic alcohols (93% to >99% ee) in 58%–91% isolated yields with minimal side reactions
Interview with Gérard Macé
No full textGérard Macé is the prize-winning author of over twenty books, as well as a respected translator and photographer, but his work is still relatively neglected in the Anglophone academy. This article, by way of a short description of his work followed by an interview with the author, seeks to introduce Macé to those who may not be acquainted with his singular and varied oeuvre. The introduction describes how Macé's writing defies generic boundaries, situating themselves somewhere between biography and autobiography, travelogue and reverie, factual account and imagined creation. His books deal with a bewildering variety of themes, often biographical: however, they always contain a first-person 'je' who, through adopting the essayist's perspective, allows his subjects' lives to unfold within the textual space created by his voice. The interview is an edited version of a long conversation in which we discussed illiteracy and language, the moment of creation in both writing and photography, the essence of the image, and the autobiographical in the biographical. Macé has been interviewed many times, but here he speaks, amongst other things, for the first time about how the key scene of Le dernier des Égyptiens emerges from an originary scene of his childhood
