Publications (85)
Nonequilibrium Work Relation from Schroedinger's Unrecognized Probability Theory
T. Koide
Jarzynski's nonequilibrium work relation can be understood as the realization of the (hidden) time-generator reciprocal symmetry satisfied for the conditional probability function.…
Quantum-classical hybrids in a simplified model of QED and geometric phase induced by charged particle trajectory
T. Koide
We derive a model of quantum-classical hybrids for a simplified model of quantum electrodynamics in the framework of the stochastic variational method. In this model, charged parti…
Anisotropic spin-density distribution and magnetic anisotropy of strained LaSrMnO thin films: Angle-dependent x-ray magnetic circular dichroism
G. Shibata, M. Kitamura, M. Minohara +21
Magnetic anisotropies of ferromagnetic thin films are induced by epitaxial strain from the substrate via strain-induced anisotropy in the orbital magnetic moment and that in the sp…
Extended Thermodynamic Relation and Fluctuation Theorem in Stochastic Dynamics with Time Reversed Process
T. Koide, M. Mine, M. Okumura +1
We consider a stochastic model described by two stochastic differential equations of motion; one is for the stochastic evolution forward in time and the other for backward in time.…
Mass Renormalization for Time Dependent Correlation Functions in Shibata-Hashitsume's Projection Operator Method
T. Koide, M. Maruyama, F. Takagi
We study the time development of correlation functions at both zero and finite temperature with Shibata-Hashitsume's projection operator method and carry out the renormalization of…
Complete Positivity and Thermal Relaxation in Quadratic Quantum Master Equations
F. Nicacio, T. Koide
The ultimate goal of this paper is to develop a systematic method for deriving quantum master equations that satisfy the requirements of a completely positive and trace-preserving…
Variational formulation of compressible hydrodynamics in curved spacetime and symmetry of stress tensor
T. Koide, T. Kodama
Hydrodynamics of the non-relativistic compressible fluid in the curved spacetime is derived using the generalized framework of the stochastic variational method (SVM) for continuum…
Memory Effects and Transport Coefficients for Non-Newtonian Fluids
T. Kodama, T. Koide
We discuss the roles of viscosity in relativistic fluid dynamics from the point of view of memory effects. Depending on the type of quantity to which the memory effect is applied,…
Microscopic formula for transport coefficients of causal hydrodynamics
T. Koide
The Green-Kubo-Nakano formula should be modified in relativistic hydrodynamics because of the problem of acausality and the breaking of sum rules. In this work, we propose a formul…
Uncertainty relation for angle from a quantum-hydrodynamical perspective
J. -P. Gazeau, T. Koide
We revisit the problem of the uncertainty relation for angle by using quantum hydrodynamics formulated in the stochastic variational method (SVM), where we need not define the angl…
Dissipative relativistic fluid dynamics: a new way to derive the equations of motion from kinetic theory
G. S. Denicol, T. Koide, D. H. Rischke
We re-derive the equations of motion of dissipative relativistic fluid dynamics from kinetic theory. In contrast to the derivation of Israel and Stewart, which considered the secon…
Bulk viscosity effects on elliptic flow
G. S. Denicol, T. Kodama, T. Koide +1
The effects of bulk viscosity on the elliptic flow are studied using realistic equation of state and realistic transport coefficients. We find that thebulk viscosity acts i…
Langevin Dynamics of Chiral Phase Transition at Finite Temperature and Density
T. Koide
We derive the linear Langevin equation to describe the dynamics of the chiral phase transition above the critical temperature by applying the projection operator method to the Namb…
Anisotropy of Low Energy Direct Photons in Relativistic Heavy Ion Collisions
T. Koide, T. Kodama
We investigate the behavior of low energy photons radiated by the deceleration processes of two colliding nuclei in relativistic heavy ion collisions using the Wigner function appr…
Thermodynamic Laws and Equipartition Theorem in Relativistic Brownian Motion
T. Koide, T. Kodama
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and…
Spectroscopic studies on the electronic and magnetic states of Co-doped perovskite manganite Pr0.8Ca0.2Mn1-yCoyO3 thin films
K. Yoshimatsu, H. Wadati, E. Sakai +13
We have investigated the electronic and magnetic properties of Co-doped Pr0.8Ca0.2MnO3 thin films using various spectroscopic techniques. X-ray absorption and hard x-ray photoemiss…
Enhancement of Critical Slowing Down in Chiral Phase Transition -- Langevin Dynamics Approach --
T. Koide, M. Maruyama
We derive the linear Langevin equation that describes the behavior of the fluctuations of the order parameter of the chiral phase transition above the critical temperature by apply…
Does canonical quantization lead to GKSL dynamics?
T. Koide, F. Nicacio
We introduce a generalized classical model of Brownian motion for describing thermal relaxation processes which is thermodynamically consistent. Applying the canonical quantization…
Noether Theorem of Relativistic-Electromagnetic Ideal Hydrodynamics
J. H. Gaspar Elsas, T. Koide, T. Kodama
We present a variational approach for relativistic ideal hydrodynamics interacting with electromagnetic fields. The momentum of fluid is introduced as the canonical conjugate varia…
Application of Stochastic Variational Method to Hydrodynamics
T. Koide
We apply the stochastic variational method to the action of the ideal fluid and showed that the Navier-Stokes equation is derived. In this variational method, the effect of dissipa…
Quantum circuit complexity for linearly polarised light
E. M. F. Curado, S. Faci, J. P. Gazeau +3
In this study, we explore a form of quantum circuit complexity that extends to open systems. To illustrate our methodology, we focus on a basic model where the projective Hilbert s…
Precursor of Color Superconductivity in Hot Quark Matter
M. Kitazawa, T. Koide, T. Kunihiro +1
We investigate possible precursory phenomena of color superconductivity in quark matter at finite temperature T with use of a simple Nambu-Jona-Lasinio model. It is found that the…
Perturbative Expansion of Irreversible Work in Fokker-Planck Equation a la Quantum Mechanics
T. Koide
We discuss the systematic expansion of the solution of the Fokker-Planck equation with the help of the eigenfunctions of the time-dependent Fokker-Planck operator. The expansion pa…
Navier-Stokes, Gross-Pitaevskii and Generalized Diffusion Equations using Stochastic Variational Method
T. Koide, T. Kodama
The stochastic variational method is applied to particle systems and continuum mediums. As the brief review of this method, we first discuss the application to particle Lagrangians…
More quantum centrifugal effect in rotating frame
J. -P. Gazeau, T. Koide, R. Murenzi
The behaviour of quantum systems in non-inertial frames is revisited from the point of view of affine coherent state (ACS) quantization. We restrict our approach to the one-particl…
Magnetic anisotropy of the van der Waals ferromagnet CrGeTe studied by angular-dependent XMCD
M. Suzuki, B. Gao, G. Shibata +12
The van der Waals ferromagnet CrGeTe (CGT) has a two-dimensional crystal structure where each layer is stacked through van der Waals force. We have investigated the nat…
Thickness-dependent magnetic properties and strain-induced orbital magnetic moment in SrRuO3 thin films
K. Ishigami, K. Yoshimatsu, D. Toyota +16
Thin films of the ferromagnetic metal SrRuO3 (SRO) show a varying easy magnetization axis depending on the epitaxial strain and undergo a metal-to-insulator transition with decreas…
Poisson bracket operator
T. Koide
We introduce the Poisson bracket operator which is an alternative quantum counterpart of the Poisson bracket. This operator is defined using the operator derivative formulated in q…
Schroedinger Equation in Rotating Frame by using Stochastic Variational Method
T. Koide, K. Tsushima, T. Kodama
We give a pedagogical introduction of the stochastic variational method by considering the quantization of a non-inertial particle system. We show that the effects of fictitious fo…
Finite-size effects on the QCD phase diagram
O. Kiriyama, T. Kodama, T. Koide
We discuss the finite-size effects on the chiral phase transition in QCD. We employ the Nambu-Jona-Lasinio model and calculate the thermodynamic potential in the mean-field approxi…
Quantum Analysis and Thermodynamic Operator Relations in Stochastic Energetics
T. Koide
We introduce a model of the quantum Brownian motion coupled to a classical neat bath by using the operator differential proposed in the quantum analysis. We then define the heat op…
Information-Geometric Quantum Process Tomography in Unital Open Single-Qubit Dynamics
T. Koide, A. van de Venn
We derive an exact information-geometric inequality valid for both Markovian and non-Markovian mixed-state dynamics. This inequality saturates into a strict equality for single qub…
Soft x-ray magnetic circular dichroism study of Ca_1-xSr_xRuO_3 across the ferromagnetic quantum phase transition
J. Okamoto, T. Okane, Y. Saitoh +10
Ca_1-xSr_xRuO_3, which is ferromagnetic for Sr concentration x > 0.3, has been studied by x-ray magnetic circular dichroism (XMCD) in Ru 3p and O 1s core-level x-ray absorption. XM…
Orbital magnetic moments in FeCr2S4 studied by x-ray magnetic circular dichroism
V. K. Verma, J. Patra, V. R. Singh +8
We have investigated the element specific magnetic characteristics of single-crystal FeCr2S4 using x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD).…
Open Problems in Hydrodynamical Approach to Relativistic Heavy Ion Collisions
T. Kodama, T. Koide, G. S. Denicol +1
We discuss some open problems in hydrodynamical approach to the relativistic heavy ion collisions. In particular, we propose a new, very simple alternative approach to the relativi…
Functional Ideal Hydrodynamics incorporating Quantum-Field Theoretical Fluctuation
T. Koide, T. Kodama
We propose new ideal hydrodynamics in the function space which describes a fluid composed of the 1+1 dimensional real scalar field in the framework of the stochastic variational me…
Stochastic Variational Method as Quantization Scheme I: Field Quantization of Complex Klein-Gordan Equation
T. Koide, T. Kodama
Stochastic Variational Method (SVM) is the generalization of the variation method to the case with stochastic variables. In the series of papers, we investigate the applicability o…
Second order dissipative fluid dynamics from kinetic theory
B. Betz, G. S. Denicol, T. Koide +3
We derive the equations of second order dissipative fluid dynamics from the relativistic Boltzmann equation following the method of W. Israel and J. M. Stewart. We present a frame…
Effects of Vector Coupling on Chiral and Color-superconducting Phase Transitions -- interplay among the scalar, pairing and vector interaction --
M. Kitazawa, T. Koide, T. Kunihiro +1
We investigate effects of the vector interaction appearing in chiral effective Lagrangians on the chiral and color superconducting (CSC) phase transitions using Nambu-Jona-Lasinio…
Cr doping-induced ferromagnetism in the spin-glass Cd1-xMnxTe studied by x-ray magnetic circular dichroism
V. K. Verma, S. Sakamoto, K. Ishikawa +7
The prototypical diluted magnetic semiconductor Cd1-xMnxTe is a spin glass (x<0.6) or an antiferromagnet (x>0.6), but becomes ferromagnetic upon doping with a small amount of Cr at…
X-ray absorption spectroscopy and X-ray magnetic circular dichroism studies of transition-metal-co-doped ZnO nano-particles
T. Kataoka, Y. Yamazaki, V. R. Singh +15
We report on x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) studies of the paramagnetic (Mn,Co)-co-doped ZnO and ferromagnetic (Fe,Co)-co-doped Zn…
Thermodynamical Relations in Function Space
T. Koide, T. Kodama
We formulate thermodynamical relations based on the field degrees of freedom by introducing a work induced by the volume change in the function space, in addition to the usual work…
Incorporating Memory Effects in Phase Separation Processes
T. Koide, G. Krein, Rudnei O. Ramos
We consider the modification of the Cahn-Hilliard equation when a time delay process through a memory function is taken into account. We then study the process of spinodal decompos…
Coarse Graining in Hydrodynamics and Effects of Fluctuations
T. Kodama, T. Koide
We address the physical meaning of hydrodynamic approach related with the coarse graining scale in the frame work of variational formulation. We point out that the local thermal eq…
Effect of bulk viscosity on Elliptic Flow near QCD phase transition
G. S. Denicol, T. Kodama, T. Koide +1
Effects of the bulk viscosity on the elliptic flow are studied. To introduce a realistic equation of state and transport coefficients, we apply the results of the lattice QCD and h…
The effect of shear and bulk viscosities on elliptic flow
G. S. Denicol, T. Kodama, T. Koide
In this work, we examine the effect of shear and bulk viscosities on elliptic flow by taking a realistic parameterization of the shear and bulk viscous coefficients, and ,…
Shear viscosity coefficient and relaxation time of causal dissipative hydrodynamics in QCD
T. Koide, E. Nakano, T. Kodama
The shear viscosity coefficient and the corresponding relaxation time for causal dissipative hydrodynamics are calculated based on the microscopic formula proposed in [T. Koide and…
Relativistic generalization of Brownian Motion
T. Koide, T. Kodama
The relativistic generalization of the Brownian motion is discussed. We show that the transformation property of the noise term is determined by requiring for the equilibrium distr…
A New Expansion of the Heisenberg Equation of Motion with Projection Operator
T. Koide, M. Maruyama
We derive a new expansion of the Heisenberg equation of motion based on the projection operator method proposed by Shibata, Hashitsume and ShingÅ«. In their projection operator met…
Relativistic Dissipative Hydrodynamics: A Minimal Causal Theory
T. Koide, G. S. Denicol, Ph. Mota +1
We present a new formalism for the theory of relativistic dissipative hydrodynamics. Here, we look for the minimal structure of such a theory which satisfies the covariance and cau…
Pseudogap of Color Superconductivity in Heated Quark Matter
M. Kitazawa, T. Koide, T. Kunihiro +1
We show that the pseudogap of the quark density of states is formed in hot quark matter as a precursory phenomenon of the color superconductivity on the basis of a low-energy effec…
Perturbative expansion of irreversible works in symmetric and asymmetric processes
T. Koide
The systematic expansion method of the solution of the Fokker-Planck equation is developed by generalizing the formulation proposed in [J. Phys. A50, 325001 (2017)]. Using this met…
Novel Effect Induced by Spacetime Curvature in Quantum Hydrodynamics
T. Koide, T. Kodama
The interplay between quantum fluctuation and spacetime curvature is shown to induce an additional quantum-curvature (QC) term in the energy-momentum tensor of fluid using the gene…
Unification of Stochastic and Quantum Thermodynamics in Scalar Field Theory via a Model with Brownian Thermostat
T. Koide, F. Nicacio
We present a systematic procedure to derive a quantum master equation for thermal relaxation in real scalar field theory, expanding on the method proposed in [Koide and Nicacio, Ph…
Quantum Smooth Boundary Forces from Constrained Geometries
J. -P. Gazeau, T. Koide, D. Noguera
We implement the so-called Weyl-Heisenberg covariant integral quantization in the case of a classical system constrained by a bounded or semi-bounded geometry. The procedure, which…
Chiral and Color-superconducting Phase Transitions with Vector Interaction in a Simple Model
M. Kitazawa, T. Koide, T. Kunihiro +1
We investigate effects of the vector interaction on chiral and color superconducting (CSC) phase transitions at finite density and temperature in a simple Nambu-Jona-Lasinio model.…
Memory Effect in Upper Bound of Heat Flux Induced by Quantum Fluctuations
T. Koide
Thermodynamic behaviors in a quantum Brownian motion coupled to a classical heat bath is studied. We then define a heat operator by generalizing the stochastic energetics and show…
Dynamical Origin of Power Spectra
T. Kodama, T. Koide
We discuss a possible origin of Tsallis' statistics from the correlation among constituents which reduces the phase space of the system. We also show that in the system of coupled…
Navier-Stokes Equation by Stochastic Variational Method
T. Koide, T. Kodama
We show for the first time that the stochastic variational method can naturally derive the Navier-Stokes equation starting from the action of ideal fluid. In the frame work of the…
Transport Coefficients of Non-Newtonian Fluid and Causal Dissipative Hydrodynamics
T. Koide, T. Kodama
A new formula to calculate the transport coefficients of the causal dissipative hydrodynamics is derived by using the projection operator method (Mori-Zwanzig formalism) in [T. Koi…
Indication of intrinsic room-temperature ferromagnetism in Ti1-xCoxO2-d thin film: An x-ray magnetic circular dichroism study
K. Mamiya, T. Koide, A. Fujimori +6
Soft x-ray magnetic circular dichroism (XMCD) measurements at the Co L2,3 edges of Co doped rutile TiO2 at room temperature have revealed clear multiplet features characteristic of…
Projection Operator Approach to Langevin Equations in Theory
T. Koide, M. Maruyama, F. Takagi
We apply the projection operator method (POM) to theory and derive both quantum and semiclassical equations of motion for the soft modes. These equations have no time-convol…
New Formulation of Causal Dissipative Hydrodynamics: Shock wave propagation
Ph. Mota, G. S. Denicol, T. Koide +1
The first 3D calculation of shock wave propagation in a homogeneous QGP has been performed within the new formulation of relativistic dissipative hydrodynamics which preserves the…
Generalization of Uncertainty Relation for Quantum and Stochastic Systems
T. Koide, T. Kodama
The generalized uncertainty relation applicable to quantum and stochastic systems is derived within the stochastic variational method. This relation not only reproduces the well-kn…
Spin-Electromagnetic Hydrodynamics and Magnetization Induced by Spin-Magnetic Interaction
T. Koide
The hydrodynamic model including the spin degree of freedom and the electromagnetic field was discussed. In this derivation, we applied electromagnetism for macroscopic medium prop…
Stability and Causality in relativistic dissipative hydrodynamics
G. S. Denicol, T. Kodama, T. Koide +1
The stability and causality of the Landau-Lifshitz theory and the Israel-Stewart type causal dissipative hydrodynamics are discussed. We show that the problem of acausality and ins…
Electronic and magnetic properties of off-stoichiometric CoMnSi/MgO interfaces studied by x-ray magnetic circular dichroism
V. R. Singh, V. K. Verma, K. Ishigami +8
We have studied the electronic and magnetic states of Co and Mn atoms at the interface of the CoMnSi (CMS)/MgO (=0.69, 0.99, 1.15 and 1.29) magnetic tunnel ju…
Proceedings of the 38th International Symposium on Multiparticle Dynamics (ISMD08)
J. Bartels, K. Borras, G. Gustafson +113
Proceedings of ISMD08
Dynamical Correlations as Origin of Nonextensive Entropy
T. Kodama, H. -T. Elze, C. E. Aguiar +1
We present a simple and general argument showing that a class of dynamical correlations give rise to the so-called Tsallis nonextensive statistics. An example of a system having su…
Viscous control of minimum uncertainty state in hydrodynamics
T. Koide
A minimum uncertainty state for position and momentum of a fluid element is obtained. We consider a general fluid described by the Navier-Stokes-Korteweg (NSK) equation, which repr…
Uncertainty Relations in Hydrodynamics
G. Gonçalves de Matos, T. Kodama, T. Koide
The uncertainty relations in hydrodynamics are numerically studied. We first give a review for the formulation of the generalized uncertainty relations in the stochastic variationa…
Memory Effect and Fast Spinodal Decomposition
T. Koide, G. Krein, Rudnei O. Ramos
We consider the modification of the Cahn-Hilliard equation when a time delay process through a memory function is taken into account. We then study the process of spinodal decompos…
Role of doped Ru in coercivity-enhanced LaSr_3$ thin film studied by x-ray magnetic circular dichroism
T. Harano, G. Shibata, K. Ishigami +15
The coercivity of LaSrMnO thin films can be enhanced by Ru substitution for Mn. In order to elucidate its mechanism, we performed soft x-ray absorption and magnetic…
Phenomenological approach to the critical dynamics of the QCD phase transition revisited
T. Koide
The phenomenological dynamics of the QCD critical phenomena is revisited. Recently, Son and Stephanov claimed that the dynamical universality class of the QCD phase transition belo…
Variational Principle of Hydrodynamics and Quantization by Stochastic Process
T. Kodama, T. Koide
The well-known hydrodynamical representation of the Schrödinger equation is reformulated by extending the idea of Nelson-Yasue's stochastic variational method. The fluid flow is c…
Extensivity of Irreversible Current and Stability in Causal Dissipative Hydrodynamics
G. S. Denicol, T. Kodama, T. Koide +1
We extended our formulation of causal dissipative hydrodynamics [T. Koide \textit{et al.}, Phys. Rev. \textbf{C75}, 034909 (2007)] to be applicable to the ultra-relativistic regime…
Linear Langevin Equation of Critical Fluctuation in Chiral Phase Transition
T. Koide, M. Maruyama
We derive the linear Langevin equation that describes the behavior of critical fluctuation above the critical temperature of the chiral phase transition in the Nambu-Jona-Lasinio m…
Precursor of Color Superconductivity
M. Kitazawa, T. Koide, T. Kunihiro +1
We investigate possible precursory phenomena of color superconductivity at finite temperature with an effective theory of QCD. It is found that the fluctuation of the diquark p…
Decay process accelerated by tunneling in its very early stage
T. Koide, F. M. Toyama
We examine a fast decay process that arises in the transition period between the Gaussian and exponential decay processes in quantum decay systems. It is usually expected that the…
Classicalization of Quantum Variables and Quantum-Classical Hybrids
T. Koide
The extraction of classical degrees of freedom in quantum mechanics is studied in the stochastic variational method. By using this classicalization, a hybrid model constructed from…
Phase diagram of CaCeMnO thin films studied by X-ray magnetic circular dichroism
T. Harano, G. Shibata, K. Yoshimatsu +14
In the perovskite-type CaCeMnO (CCMO), one can control the transport and magnetic properties through varying Ce content. In the case of thin films, the properti…
Microscopic Derivation of Causal Diffusion Equation using Projection Operator Method
T. Koide
We derive a coarse-grained equation of motion of a number density by applying the projection operator method to a non-relativistic model. The derived equation is an integrodifferen…
Possible Enhancements of Collective Flow Anisotropy Induced by Uncertainty Relation for Fluid Element
G. G. Matos, T. Koide, T. Kodama
In the stochastic formulation of viscous hydrodynamics, the velocity of a fluid element fluctuates satisfying a similar relation to the quantum-mechanical uncertainty relation. Usi…
Shock propagation and stability in causal dissipative hydrodynamics
G. S. Denicol, T. Kodama, T. Koide +1
We studied the shock propagation and its stability with the causal dissipative hydrodynamics in 1+1 dimensional systems. We show that the presence of the usual viscosity is not eno…
Time Evolution of Heat Conduction in a Generalized Model of Brownian Motion
T. Koide, F. Nicacio
We investigate the properties of heat conduction in a network of harmonic oscillators interacting with heat baths, described by a generalized model of Brownian motion. This model i…