Resonant states of open quantum systems (2009)
We first show that quantum resonant states observe particle number conservation and hence are consistent with the probabilistic interpretation of quantum mechanics. We then present for a class of...
Distribution of Resonant Eigenvalues of Quantum Potential Scattering (2009)
We formulate the Born approximation for finding resonance poles in the complex plane for potential scattering problems. Using the method, we study the distribution of resonance poles for several...
Quantum Nernst Effect in a Bismuth Single Crystal (2009)
Matsuo, Mari, Endo, Akira, Hatano, Naomichi, Nakamura, Hiroaki, Shirasaki, Ryoen, Sugihara, Ko
We calculate the phonon-drag contribution to the transverse (Nernst) thermoelectric power $S_{yx}$ in a bismuth single crystal subjected to a quantizing magnetic field. The calculated heights of the...
Endo, Akira, Hatano, Naomichi, Nakamura, Hiroaki, Shirasaki, Ryoen
We investigate the relation between the diagonal ($\sigma_{xx}$) and off-diagonal ($\sigma_{xy}$) components of the conductivity tensor in the quantum Hall system. We calculate the conductivity...
Communicability and Communities in Complex Socio-Economic Networks (2009)
Estrada, Ernesto, Hatano, Naomichi
The concept of communicability is introduced for complex socio-economic networks. The communicability function expresses how an impact propagates from one place to another in the network. This...
Sasada, Keita, Hatano, Naomichi, Ordonez, Gonzalo
The main purpose of the present paper is to analyze the conductance of an $N$-site quantum dot with multiple semi-infinite leads. First, we obtain a simple conductance formula that contains only the...
"Clumpiness" Mixing in Complex Networks (2009)
Estrada, Ernesto, Hatano, Naomichi, Gutierrez, Amauri
Three measures of clumpiness of complex networks are introduced. The measures quantify how most central nodes of a network are clumped together. The assortativity coefficient defined in a previous...
Statistical-mechanical approach to subgraph centrality in complex networks (2009)
Estrada, Ernesto, Hatano, Naomichi
We interpret the subgraph centrality as the partition function of a network. The entropy, the internal energy and the Helmholtz free energy are defined for networks and molecular graphs on the basis...
Estrada, Ernesto, Hatano, Naomichi
An electronic orbital of a dihedral angle of a molecular chain is introduced. A tight-binding Hamiltonian on the basis of the dihedral orbitals is defined. This yields the Green's function between...
Estrada, Ernesto, Higham, Desmond J., Hatano, Naomichi
We here present a method of clearly identifying multi-partite subgraphs in a network. The method is based on a recently introduced concept of the communicability, which very clearly identifies...
Communicability Betweenness in Complex Networks (2009)
Estrada, Ernesto, Higham, Desmond J., Hatano, Naomichi
Betweenness measures provide quantitative tools to pick out fine details from the massive amount of interaction data that is available from large complex networks. They allow us to study the extent...
Communicability Graph and Community Structures in Complex Networks (2009)
Estrada, Ernesto, Hatano, Naomichi
We use the concept of the network communicability (Phys. Rev. E 77 (2008) 036111) to define communities in a complex network. The communities are defined as the cliques of a communicability graph,...
Existence and nonexistence of an intrinsic tunneling time (2009)
Ordonez, Gonzalo, Hatano, Naomichi
Using a time operator, we define a tunneling time for a particle going through a barrier. This tunneling time is the average of the phase time introduced by other authors. In addition to the delay...
Nishino, Akinori, Imamura, Takashi, Hatano, Naomichi
We obtain an exact many-body scattering eigenstate in an open quantum dot system. The scattering state is not in the form of the Bethe eigenstate in the sense that the wave-number set of the incoming...
Entanglement generation through an open quantum dot: an exact approach (2009)
Imamura, Takashi, Nishino, Akinori, Hatano, Naomichi
We analytically study entanglement generation through an open quantum dot system described by the two-lead Anderson model. We exactly obtain the transition rate between the non-entangled incident...
The exchange fluctuation theorem in quantum mechanics (2009)
Akagawa, Shiho, Hatano, Naomichi
We study the heat transfer between two finite quantum systems initially at different temperatures. We find that a recently proposed fluctuation theorem for heat exchange, namely the exchange...
Calculation of the Self-energy of Open Quantum Systems (2009)
Sasada, Keita, Hatano, Naomichi
We propose an easy method of calculating the self-energy of semi-infinite leads attached to a mesoscopic system.
Probabilistic Interpretation of Resonant States (2009)
Hatano, Naomichi, Kawamoto, Tatsuro, Feinberg, Joshua
We provide probabilistic interpretation of resonant states. This we do by showing that the integral of the modulus square of resonance wave functions (i.e., the conventional norm) over a properly...
Quantum Nernst effect in a bismuth single crystal (2008)
Matsuo, Mari, Endo, Akira, Hatano, Naomichi, Nakamura, Hiroaki, Shirasaki, Ryoen, Sugihara, Ko
We report a theoretical calculation explaining the quantum Nernst effect observed experimentally in a bismuth single crystal. Generalizing the edge-current picture in two dimensions, we show that the...
Vortex generation in the RSP game on the triangular lattice (2008)
Nishiuchi, Hiroyuki, Hatano, Naomichi, Kubo, Kenn
A new model of population dynamics on lattices is proposed. The model consists of players on lattice points, each of which plays the RSP game with neighboring players. Each player copies the next...
Transient Oscillation of Currents in Quantum Hall Effect of Bloch Electrons (2007)
Machida, Manabu, Goryo, Jun, Hatano, Naomichi
We consider the quantum Hall effect of two-dimensional electrons with a periodic potential and study the time dependence of the Hall and longitudinal currents when the electric field is applied...
Quasi-bound states in continuum (2007)
Nakamura, Hiroaki, Hatano, Naomichi, Garmon, Sterling, Petrosky, Tomio
We report the prediction of quasi-bound states (resonant states with very long lifetimes) that occur in the eigenvalue continuum of propagating states for a wide region of parameter space. These...
Communicability in complex networks (2007)
Estrada, Ernesto, Hatano, Naomichi
Many topological and dynamical properties of complex networks are defined by assuming that most of the transport on the network flows along the shortest paths. However, there are different scenarios...
The entanglement of the XY spin chain in a random magnetic field (2007)
Fujinaga, Masashi, Hatano, Naomichi
We investigate the entanglement of the ferromagnetic XY model in a random magnetic field at zero temperature and in the uniform magnetic field at finite temperatures. We use the concurrence to...
Resonance in an open quantum dot system with a Coulomb interaction: a Bethe-ansatz approach (2007)
Nishino, Akinori, Hatano, Naomichi
An open quantum system consisting of a quantum dot with a Coulomb interaction and two leads without interactions is studied. The many-body scattering states are constructed with the Bethe-ansatz...
Some properties of the resonant state in quantum mechanics and its computation (2007)
Hatano, Naomichi, Sasada, Keita, Nakamura, Hiroaki, Petrosky, Tomio
The resonant state of the open quantum system is studied from the viewpoint of the outgoing momentum flux. We show that the number of particles is conserved for a resonant state, if we use an...
Non-Abelian gauge field theory of the spin-orbit interaction and a perfect spin filter (2007)
Hatano, Naomichi, Shirasaki, Ryoen, Nakamura, Hiroaki
We point out that the Rashba and Dresselhaus spin-orbit interactions in two dimensions can be regarded as a Yang-Mills non-Abelian gauge field. The physical field generated by the gauge field gives...
Gap-mediated magnetization of a pseudo-one-dimensional system with a spin-orbit interaction (2006)
Hatano, Naomichi, Shirasaki, Ryoen, Nakamura, Hiroaki
We argue that a pseudo-one-dimensional electron gas is magnetized when a voltage bias is applied with the Fermi level tuned to be in the energy gap generated by a spin-orbit interaction. The...
Nakamura, Yuichi, Hatano, Naomichi
We study a non-Hermitian generalization of quantum systems in which an imaginary vector potential is added to the momentum operator. In the tight-binding approximation, we make the hopping energy...
Temporal Oscillation of Conductances in Quantum Hall Effect of Bloch Electrons (2006)
Machida, Manabu, Hatano, Naomichi, Goryo, Jun
We study a nonadiabatic effect on the conductances in the quantum Hall effect of two-dimensional electrons with a periodic potential. We found that the Hall and longitudinal conductances oscillate in...
A non-Hermitian analysis of strongly correlated quantum systems (2006)
Nakamura, Yuichi, Hatano, Naomichi
We study a non-Hermitian generalization of strongly correlated quantum systems in which the transfer energy of electrons is asymmetric. It is known that a non-Hermitian critical point is equal to the...
Nakamura, Hiroaki, Hatano, Naomichi, Shirasaki, Ryoen
We report our recent predictions on the quantum Nernst effect, a novel thermomagnetic effect in the quantum Hall regime. We assume that, when the chemical potential is located between a pair of...
Strong Resonance of Light in a Cantor Set (2005)
The propagation of an electromagnetic wave in a one-dimensional fractal object, the Cantor set, is studied. The transfer matrix of the wave amplitude is formulated and its renormalization...
Nakamura, Hiroaki, Hatano, Naomichi, Shirasaki, Ryoen
It is theoretically predicted that the Nernst coefficient is strongly suppressed and the thermal conductance is quantized in the quantum Hall regime of the two-dimensional electron gas. The Nernst...
Finding Exponential Product Formulas of Higher Orders (2005)
Hatano, Naomichi, Suzuki, Masuo
In the present article, we review a continual effort on generalization of the Trotter formula to higher-order exponential product formulas. The exponential product formula is a good and useful...
Models of Universal Power-Law Distributions (2003)
Kawamura, Kenji, Hatano, Naomichi
Power-law distributions with various exponents are studied. We first introduce a simple and generic model that reproduces Zipf's law. We can regard this model both as the time evolution of the...
Universality of Zipf's Law (2002)
Kawamura, Kenji, Hatano, Naomichi
We introduce a simple and generic model that reproduces Zipf's law. By regarding the time evolution of the model as a random walk in the logarithmic scale, we explain theoretically why this model...
Triangular arbitrage as an interaction among foreign exchange rates (2002)
Aiba, Yukihiro, Hatano, Naomichi, Takayasu, Hideki, Marumo, Kouhei, Shimizu, Tokiko
We first show that there are in fact triangular arbitrage opportunities in the spot foreign exchange markets, analyzing the time dependence of the yen-dollar rate, the dollar-euro rate and the...
Evidence for the double degeneracy of the ground-state in the 3D $\pm J$ spin glass (2000)
Hatano, Naomichi, Gubernatis, James E.
A bivariate version of the multicanonical Monte Carlo method and its application to the simulation of the three-dimensional $\pm J$ Ising spin glass are described. We found the autocorrelation time...
Non-Adiabatic Transition in Spin-Boson Model and Generalization of the Landau-Zener Formula (1998)
Kobayashi, Hiroto, Hatano, Naomichi, Miyashita, Seiji
Non-adiabatic transitions are studied in a spin-boson model with multiple scattering points. In order to generalize the Landau-Zener formula, which describes the case of a single scattering point, we...
Non-Hermitian Delocalization and Eigenfunctions (1998)
Hatano, Naomichi, Nelson, David R.
Recent literature on delocalization in non-Hermitian systems has stressed criteria based on sensitivity of eigenvalues to boundary conditions and the existence of a non-zero current. We emphasize...
Localization in non-Hermitian quantum mechanics and flux-line pinning in superconductors (1998)
A recent development in studies of random non-Hermitian quantum systems is reviewed. Delocalization was found to occur under a sufficiently large constant imaginary vector potential even in one and...
Vortex Pinning and Non-Hermitian Quantum Mechanics (1997)
Hatano, Naomichi, Nelson, David R.
A delocalization phenomenon is studied in a class of non-Hermitian random quantum-mechanical problems. Delocalization arises in response to a sufficiently large constant imaginary vector potential....
Extrapolation-CAM Theory for Critical Exponents (1997)
Richards, Howard L., Hatano, Naomichi, Novotny, M. A.
By intentionally underestimating the rate of convergence of exact-diagonalization values for the mass or energy gaps of finite systems, we form families of sequences of gap estimates. The gap...
Localization transitions in non-Hermitian quantum mechanics (1996)
Hatano, Naomichi, Nelson, David R.
We study the localization transitions which arise in both one and two dimensions when quantum mechanical particles described by a random Schr\"odinger equation are subjected to a constant imaginary...
Hidden Orders and RVB Formation of the Four-Leg Heisenberg Ladder Model (1995)
Nishiyama, Yoshihiro, Hatano, Naomichi, Suzuki, Masuo
The ground state of the four-chain Heisenberg ladder model is numerically investigated. Hidden-order correlations suitable for the system are introduced and calculated with an emphasis on the...
Nakamura, Hiroaki, Hatano, Naomichi, Takahashi, Minoru
The finite-size scaling function of the nonlinear susceptibility of the ferromagnetic Heisenberg chain is given explicitly. It is conjectured that the scaling function is universal for any values of...
Scaling Theory of Antiferromagnetic Heisenberg Ladder Models (1995)
Hatano, Naomichi, Nishiyama, Yoshihiro
The $S=1/2$ antiferromagnetic Heisenberg model on multi-leg ladders is investigated. Criticality of the ground-state transition is explored by means of finite-size scaling. The ladders with an even...
Triangular arbitrage as an interaction among foreign exchange rates
Yukihiro Aiba, Naomichi Hatano, Hideki Takayasu, Kouhei Marumo, Tokiko Shimizu
We first show that there are in fact triangular arbitrage opportunities in the spot foreign exchange markets, analyzing the time dependence of the yen-dollar rate, the dollar-euro rate and the...