Microscopic Theory of Skyrmions in Quantum Hall Ferromagnets

We present a microscopic theory of skyrmions in the monolayer quantum Hall ferromagnet. It is a peculiar feature of the system that the number density and the spin density are entangled intrinsically as dictated by the W$$ algebra. The skyrmion and antiskyrmion states are constructed as W$_{\infty }$-rotated states of the hole-excited and electron-excited states, respectively. They are spin textures accompanied with density modulation that decreases the Coulomb energy. We calculate their excitation energy as a function of the Zeeman gap and compared the result with experimental data.Comment: 15 pages (to be published in PRB

Citrullinated fibrinogen shows defects in FPA and FPB release and fibrin polymerization catalyzed by thrombin

ArticleClinica Chimica Acta. 401(1-2):119-123 (2009)journal articl

Residue gamma 153Cys is essential for the formation of the complexes A alpha gamma and B beta gamma, assembly intermediates for the A alpha B beta gamma complex and intact fibrinogen

ArticleCLINICA CHIMICA ACTA. 353(1-2): 157-164 (2005)journal articl

In vitro fibrin clot formation and fibrinolysis using heterozygous plasma fibrinogen from gamma Asn319, Asp320 deletion dysfibrinogen, Otsu I

ArticleTHROMBOSIS RESEARCH. 118(5): 651-661 (2006)journal articl

Substitution of the gamma-chain Asn308 disturbs the D : D interface affecting fibrin polymerization, fibrinopeptide B release, and FXIIIa-catalyzed cross-linking

This research was originally published in Blood. Authors. Okumura, N; Gorkun, OV; Terasawa, F; Lord, ST Title. Blood. 2004; 103(12): 4157-4163. © by the American Society of Hematology.ArticleBLOOD. 103(11): 4157-4163 (2004)journal articl

Magnetotransport Study of the Canted Antiferromagnetic Phase in Bilayer ν=2\nu=2 Quantum Hall State

Magnetotransport properties are investigated in the bilayer quantum Hall state at the total filling factor $\nu=2$. We measured the activation energy elaborately as a function of the total electron density and the density difference between the two layers. Our experimental data demonstrate clearly the emergence of the canted antiferromagnetic (CAF) phase between the ferromagnetic phase and the spin-singlet phase. The stability of the CAF phase is discussed by the comparison between experimental results and theoretical calculations using a Hartree-Fock approximation and an exact diagonalization study. The data reveal also an intrinsic structure of the CAF phase divided into two regions according to the dominancy between the intralayer and interlayer correlations.Comment: 6 pages, 7 figure

Collective modes of CP(3) Skyrmion crystals in quantum Hall ferromagnets

The two-dimensional electron gas in a bilayer quantum Hall system can sustain an interlayer coherence at filling factor nu=1 even in the absence of tunneling between the layers. This system has low-energy charged excitations which may carry textures in real spin or pseudospin. Away from filling factor nu =1 a finite density of these is present in the ground state of the 2DEG and forms a crystal. Depending on the relative size of the various energy scales, such as tunneling (Delta_SAS), Zeeman coupling (Delta_Z) or electrical bias (Delta_b), these textured crystal states can involve spin, pseudospin, or both intertwined. In this article, we present a comprehensive numerical study of the collective excitations of these textured crystals using the GRPA. For the pure spin case, at finite Zeeman coupling the state is a Skyrmion crystal with a gapless phonon mode, and a separate Goldstone mode that arises from a broken U(1) symmetry. At zero Zeeman coupling, we demonstrate that the constituent Skyrmions break up, and the resulting state is a meron crystal with 4 gapless modes. In contrast, a pure pseudospin Skyrme crystal at finite tunneling has only the phonon mode. For Delta_SAS=0, the state evolves into a meron crystal and supports an extra gapless U(1) mode in addition to the phonon. For a CP(3) Skyrmion crystal, we find a U(1) gapless mode in the presence of the symmetry-breaking fields. In addition, a second mode with a very small gap is present in the spectrum.Comment: 16 pages and 12 eps figure

Analysis of fibrinogen variants at gamma 387Ile shows that the side chain of gamma 387 and the tertiary structure of the gamma C-terminal tail are important not only for assembly and secretion of fibrinogen but also for lateral aggregation of protofibrils and XIIIa-catalyzed gamma-gamma dimer formation

This research was originally published in Blood. Author(s).Kani, S; Terasawa, F; Yamauchi, K; Tozuka, M; Okumura, N. Title. Blood. 2006;108:1887-1894. © by the American Society of Hematology.ArticleBLOOD. 108(6): 1887-1894 (2006)journal articl