Thermoelectricity by Perfectly Conducting Channels in Quantum Spin Hall Systems (2009)
Takahashi, Ryuji, Murakami, Shuichi
Thermoelectric transport of two-dimensional quantum spin Hall systems are theoretically studied in narrow ribbon geometry. We find that at high temperature electrons in the bulk states dominate. By...
Kohn Anomalies in Graphene Nanoribbons (2009)
Sasaki, Ken-ichi, Yamamoto, Masayuki, Murakami, Shuichi, Saito, Riichiro, Dresselhaus, Mildred S., Takai, Kazuyuki, ...
The quantum corrections to the energies of the $\Gamma$ point optical phonon modes (Kohn anomalies) in graphene nanoribbons are investigated. We show theoretically that the longitudinal optical modes...
Quantum spin Hall phases (2009)
We review our recent theoretical works on the the quantum spin Hall effect. First we compare edge states in various 2D systems, and see whether they are robust or fragile against perturbations....
Spin Hall Effect of Excitons (2008)
Kuga, Shun-ichi, Murakami, Shuichi, Nagaosa, Naoto
Spin Hall effect for excitons in alkali halides and in Cu_2O is investigated theoretically. In both systems, the spin Hall effect results from the Berry curvature in k space, which becomes nonzero...
Disorder effect on 3-dimensional $Z_2$ quantum spin Hall systems (2008)
Shindou, Ryuichi, Murakami, Shuichi
In this paper, we studied the nonmagnetic disorder effects onto the quantum critical point (QCP) which intervenes an ordinary insulator and the 3-dimensional $Z_2$ quantum spin Hall insulator. The...
Universal phase diagrams for the quantum spin Hall systems (2008)
Murakami, Shuichi, Kuga, Shun-ichi
We describe how the three-dimensional quantum spin Hall phase arises from the insulator phase by changing an external parameter. In 3D systems without inversion symmetry, a gapless phase should...
Murakami, Reiichi, Murakami, Shuichi, Tsushima, Rumi, Ueda, Chiyuki, Mikami, Kyoko, Ebina, Takanori, ...
Background. Osteodystrophy is one of the long-term haemodialysis complications, and in diabetic patients, it mainly occurs as an aplastic or low-turnover type due to their low serum intact...
Frank Gohmann, Shuichi Murakami
Fermionic representations of integrable lattice systems
Electron Correlation and Jahn-Teller Interaction in Manganese Oxides (2007)
Naoto Nagaosa, Shuichi Murakami, Hyun Cheol Lee
The interplay between the electron repulsion U and the Jahn-Teller electronphonon interation ELR is studied with a large d model for the ferromagnetic state of the manganese oxides. These two...
Phase transitions between the quantum spin Hall and the insulator phases in three dimensions are studied. We find that in inversion-asymmetric systems there appears a gapless phase between the...
Tuning phase transition between quantum spin Hall and ordinary insulating phases (2007)
Murakami, Shuichi, Iso, Satoshi, Avishai, Yshai, Onoda, Masaru, Nagaosa, Naoto
An effective theory is constructed for analyzing a generic phase transition between the quantum spin Hall and the insulator phases. Occurrence of degeneracies due to closing of the gap at the...
Quantum charge pumping and electric polarization in Anderson insulators (2007)
Chern, Chyh-Hong, Onoda, Shigeki, Murakami, Shuichi, Nagaosa, Naoto
We investigate adiabatic charge pumping in disordered system in one dimension with open and closed boundary conditions. In contrast to the Thouless charge pumping, the system has no gap even though...
Quantum Spin Hall Effect and Enhanced Magnetic Response by Spin-Orbit Coupling (2006)
We show that the spin Hall conductivity in insulators is related with a magnetic susceptibility representing the strength of the spin-orbit coupling. We use this relationship as a guiding principle...
Geometrical Aspects in Optical Wavepacket Dynamics (2006)
Onoda, Masaru, Murakami, Shuichi, Nagaosa, Naoto
We construct a semiclassical theory for propagation of an optical wavepacket in non-conducting media with periodic structures of dielectric permittivity and magnetic permeability, i.e.,...
Enhanced dielectric response by disordered nanoscale/mesoscopic insulators (2006)
Onoda, Shigeki, Chern, Chyh-Hong, Murakami, Shuichi, Ogimoto, Yasushi, Nagaosa, Naoto
Enhancement of the dielectric response of insulators by disorder is theoretically proposed, where the quantum interference of electronic waves through the nanoscale/mesoscopic system and its change...
Gauge field for edge state in graphene (2006)
Sasaki, Ken-ichi, Murakami, Shuichi, Saito, Riichiro
By considering the continuous model for graphene, we analytically study a special gauge field for the edge state. The gauge field explains the properties of the edge state such as the existence only...
Dynamical Diffraction Theory for Wave Packet Propagation in Deformed Crystals (2006)
Sawada, Kei, Murakami, Shuichi, Nagaosa, Naoto
We develop a theory for the trajectory of an x ray in the presence of a crystal deformation. A set of equations of motion for an x-ray wave packet including the dynamical diffraction is derived,...
Spin-Hall effect: Back to the Beginning on a Higher Level (2005)
Sinova, Jairo, Murakami, Shuichi, Shen, Shun-Qing, Choi, Mahn-Soo
The phenomena of the spin-Hall effect, initially proposed over three decades ago in the context of asymmetric Mott skew scattering, was revived recently by the proposal of a possible intrinsic...
Intrinsic Spin Hall Effect (2005)
A brief review is given on the spin Hall effect, where an external electric field induces a transverse spin current. It has been recognized over 30 years that such effect occurs due to impurities in...
Spin Hall effect of conserved current: Conditions for a nonzero spin Hall current (2005)
Sugimoto, Naoyuki, Onoda, Shigeki, Murakami, Shuichi, Nagaosa, Naoto
We study the spin Hall effect taking into account the impurity scattering effect as general as possible with the focus on the definition of the spin current. The conserved bulk spin current (Shi et...
Re-parameterization Invariance in Fractional Flux Periodicity (2004)
Murakami, Shuichi, Sasaki, Ken-ichi, Saito, Riichiro
We analyze a common feature of a nontrivial fractional flux periodicity in two-dimensional systems. We demonstrate that an addition of fractional flux can be absorbed into re-parameterization of...
Murakami, Shuichi, Nagaosa, Naoto, Zhang, Shou-Cheng
Recent theories predict dissipationless spin current induced by an electric field in doped semiconductors. Nevertheless, the charge current is still dissipative in these systems. In this work, we...
Onoda, Masaru, Murakami, Shuichi, Nagaosa, Naoto
We derive the semiclassical equation of motion for the wave-packet of light taking into account the Berry curvature in the momentum space. This equation naturally describes the interplay between the...
Absence of vertex correction for the spin Hall effect in p-type semiconductors (2004)
We calculate an effect of spinless impurities on the spin Hall effect of the Luttinger model representing p-type semiconductors. The self-energy in the Born approximation becomes diagonal in the...
Spin Hall Effect in p-type Semiconductors (2004)
The spin Hall effect is a phenomenon of inducing spin current by an external electric field. We recently proposed that this effect can occur in p-type semiconductors without relying upon any disorder...
Topological nature of polarization and charge pumping in ferroelectrics (2004)
Onoda, Shigeki, Murakami, Shuichi, Nagaosa, Naoto
Electric polarization or transferred charge due to an adiabatic change of external parameters $\vec{Q}$ is expressed in terms of a vector field defined in the $\vec{Q}$ space. This vector field is...
SU(2) Non-Abelian Holonomy and Dissipationless Spin Current in Semiconductors (2003)
Murakami, Shuichi, Nagaosa, Naoto, Zhang, Shou-Cheng
Following our previous work [S. Murakami, N. Nagaosa, S. C. Zhang, Science 301, 1348 (2003)] on the dissipationless quantum spin current, we present an exact quantum mechanical calculation of this...
Dissipationless Quantum Spin Current at Room Temperature (2003)
Murakami, Shuichi, Nagaosa, Naoto, Zhang, Shou-Cheng
While microscopic laws of physics are invariant under the reversal of the arrow of time, the transport of energy and information in most devices is an irreversible process. It is this irreversibility...
Colossal magnetoresistance in manganites as a multicritical phenomenon (2002)
Murakami, Shuichi, Nagaosa, Naoto
The colossal magnetoresistance in manganites AMnO_3 is studied from the viewpoint of multicritical phenomena. To understand the complicated interplay of various phases, we study the Ginzburg-Landau...
Berry phase in Magnetic Superconductors (2002)
Murakami, Shuichi, Nagaosa, Naoto
In magnetic systems, electronic bands often acquire nontrivial topological structure characterized by gauge flux distribution in momentum (k)-space. It sometimes follows that the phase of the...
Theory of Excitonic States in CaB6 (2002)
Murakami, Shuichi, Shindou, Ryuichi, Nagaosa, Naoto, Mishchenko, Andrei S.
We study the excitonic states in CaB6 in terms of the Ginzburg-Landau theory. By minimizing the free energy and by comparing with experimental results, we identify two possible ground states with...
Theory of Ferromagnetism in Ca1-xLaxB6 (2001)
Murakami, Shuichi, Shindou, Ryuichi, Nagaosa, Naoto, Mishchenko, Andrei S.
Novel ferromagnetism in Ca$_{1-x}$La$_{x}$B$_6$ is studied in terms of the Ginzburg-Landau theory for excitonic order parameters, taking into account symmetry of the wavefunctions. We found that the...
Ohgushi, Kenya, Murakami, Shuichi, Nagaosa, Naoto
A ferromagnet with spin anisotropies on the 2D Kagome lattice is theoretically studied. This is a typical example of the flat-band ferromagnet. The Berry phase induced by the tilting of the spins...
Murakami, Shuichi, Nagaosa, Naoto
We study theoretically the multicritical phenomena of the superconductivity (SC) and antiferromagnetism (AF) in organic conductors $\kappa$-BEDT salts. The phase diagram and the experimental data on...
An SO(5) model of p-wave superconductivity and ferromagnetism (1998)
Murakami, Shuichi, Nagaosa, Naoto, Sigrist, Manfred
We study an SO(5) model unifying p-wave superconductivity and ferromagnetism. If only a single p-wave pairing wavefunction is involved, the p-wave superconducting (pSC) and ferromagnetic (F) states...
Fermionic representations of integrable lattice systems (1998)
Göhmann, Frank, Murakami, Shuichi
We develop a general scheme for the use of Fermi operators within the framework of integrable systems. This enables us to read off a fermionic Hamiltonian from a given solution of the Yang-Baxter...
Lattice Instability in the Spin-Ladder System under Magnetic Field (1998)
Nagaosa, Naoto, Murakami, Shuichi
We study theoretically the lattice instability in the spin gap systems under magnetic field. With the magnetic field larger than a critical value h_{c1}, the spin gap is collapsed and the...
New integrable extension of the Hubbard chain with variable range hopping (1998)
New integrable variant of the one-dimensional Hubbard model with variable-range correlated hopping is studied. The Hamiltonian is constructed by applying the quantum inverse scattering method on the...
New integrable extension of the Hubbard chain with variable range hopping (1998)
New integrable variant of the one-dimensional Hubbard model with variable-range correlated hopping is studied. The Hamiltonian is constructed by applying the quantum inverse scattering method on the...
Lattice Instability in the Spin-Ladder System under Magnetic Field (1998)
Naoto Nagaosa, Shuichi Murakami
We study theoretically the lattice instability in the spin gap systems under magnetic field. With the magnetic field larger than a critical value h c1 , the spin gap is collapsed and the...
Electron Correlation and Jahn-Teller Interaction in Manganese Oxides (1997)
Nagaosa, Naoto, Murakami, Shuichi, Lee, Hyun Cheol
The interplay between the electron repulsion $U$ and the Jahn-Teller electron-phonon interation $E_{LR}$ is studied with a large $d$ model for the ferromagnetic state of the manganese oxides. These...
Algebraic Solution of the Hubbard Model on the Infinite Interval (1997)
Murakami, Shuichi, Göhmann, Frank
We develop the quantum inverse scattering method for the one-dimensional Hubbard model on the infinite line at zero density. This enables us to diagonalize the Hamiltonian algebraically. The...
Algebraic Solution of the Hubbard Model on the Infinite Interval (1997)
Shuichi Murakami, Frank Göhmann
We develop the quantum inverse scattering method for the one-dimensional Hubbard model on the infinite line at zero density. This enables us to diagonalize the Hamiltonian algebraically. The...
Algebraic and Analytic Properties of the One-Dimensional Hubbard Model (1996)
Göhmann, Frank, Murakami, Shuichi
We reconsider the quantum inverse scattering approach to the one-dimensional Hubbard model and work out some of its basic features so far omitted in the literature. It is our aim to show that...
Yangian Symmetry and Quantum Inverse Scattering Method for the One-Dimensional Hubbard Model (1996)
Murakami, Shuichi, Göhmann, Frank
We develop the quantum inverse scattering method for the one-dimensional Hubbard model on the infinite interval at zero density. $R$-matrix and monodromy matrix are obtained as limits from their...
Yangian Symmetry and Quantum Inverse Scattering Method for the One-Dimensional Hubbard Model (1996)
Shuichi Murakami, Frank G Ohmann
We develop the quantum inverse scattering method for the one-dimensional Hubbard model on the infinite interval at zero density. R-matrix and monodromy matrix are obtained as limits from their known...