Naoko NAKAGAWAProfessor

■Researcher basic information

Organization

  • College of Science Department of Sciences Physics
  • Graduate School of Science and Engineering（Master's Program） Major in Quantum Bean Science
  • Graduate School of Science and Engineerin（Doctoral Program） Major in Quantum Bean Science
  • Faculty of Basic Natural Science Domain of Physics

Research Areas

  • Natural sciences, Mathematical physics and basic theory, Mathematical physics/Fundamental condensed matter physics

Research Keyword

  • 統計力学基礎論（特に非平衡定常系への拡張）、 タンパク質の揺らぎと機能、非平衡現象一般

Degree

  • 1996年03月　博士（理学）（京都大学）
  • 1993年03月　修士（理学）（京都大学）

■Research activity information

Paper

  • Non-equilibrium Phase Coexistence in Boundary-Driven Diffusive Systems
    Shin-ichi Sasa; Naoko Nakagawa
    Journal of Statistical Physics, 03 Feb. 2025, [Reviewed]
  • Heat-Induced Liquid Hovering in Liquid-Gas Coexistence under Gravity
    Akira Yoshida; Naoko Nakagawa; Shin-ichi Sasa, Corresponding
    Physical Review Letters, 10 Sep. 2024, [Reviewed]
  • Control of Metastable States by Heat Flux in the Hamiltonian Potts Model
    Michikazu Kobayashi; Naoko Nakagawa; Shin-ichi Sasa, American Physical Society (APS)
    Physical Review Letters, 15 Jun. 2023
  • Quasi-static Decomposition and the Gibbs Factorial in Small Thermodynamic Systems
    Shin-ichi Sasa; Ken Hiura; Naoko Nakagawa; Akira Yoshida, Abstract

    For a classical system consisting of N-interacting identical particles in contact with a heat bath, we define the free energy from thermodynamic relations in equilibrium statistical mechanics. Concretely, the temperature dependence of the free energy is determined from the Gibbs-Helmholtz relation, and its volume dependence is determined from the condition that the quasi-static work in a volume change is equal to the free energy change. Now, we argue the free energy difference in a quasi-static decomposition of small thermodynamic systems. We can then determine the N dependence of the free energy, which includes the Gibbs factorial N! in addition to the phase space integration of the Gibbs–Boltzmann factor., Springer Science and Business Media LLC
    Journal of Statistical Physics, 21 Sep. 2022, [Reviewed]
  • Unique extension of the maximum entropy principle to phase coexistence in heat conduction
    Naoko Nakagawa and Shin-ichi Sasa, Lead, American Physical Society (APS)
    Physical Review Research, 29 Aug. 2022, [Reviewed]
  • Work relation for determining the mixing free energy of small-scale mixtures
    Akira Yoshida; Naoko Nakagawa, Last
    Physical Review Research, 13 May 2022, [Reviewed]
  • Stochastic order parameter dynamics for phase coexistence in heat conduction
    Shin-ichi Sasa; Naoko Nakagawa; Masato Itami; and Yohei Nakayama, American Physical Society (APS)
    Physical Review E, 16 Jun. 2021, [Reviewed]
  • Effective Langevin equations leading to large deviation function of time-averaged velocity for a nonequilibrium Rayleigh piston
    Masato Itami; Yohei Nakayama; Naoko Nakagawa; and Shin-ichi Sasa, We study fluctuating dynamics of a freely movable piston that separates an infinite cylinder into two regions filled with ideal gas particles at the same pressure but different temperatures. To investigate statistical properties of the time-averaged velocity of the piston in the long-time limit, we perturbatively calculate the large deviation function of the time-averaged velocity. Then, we derive an infinite number of effective Langevin equations yielding the same large deviation function as in the original model. Finally, we provide two possibilities for uniquely determining the form of the effective model., AMER PHYSICAL SOC
    Physical Review E, 12 Feb. 2021, [Reviewed]
  • Multiplicative Langevin Equation to Reproduce Long-time Properties of Nonequi- librium Brownian Motion
    Atsumasa Seya; Tatsuya Aoyagi; Masato Itami; Yohei Nakayama and Naoko Nakagawa, Last, We statistically examine long time sequences of Brownian motion for a nonequilibrium version of the Rayleigh piston model and confirm that the third cumulant of a long-time displacement for the nonequilibrium Brownian motion linearly increases with the observation time interval. We identify a multiplicative Langevin equation that can reproduce the cumulants of the long-time displacement up to at least the third order, as well as its mean, variance and skewness. The identified Langevin equation involves a velocity-dependent friction coefficient that breaks the time-reversibility and may act as a generator of the directionality. Our method to find the Langevin equation is not specific to the Rayleigh piston model but may be applied to a general time sequence in various fields., IOP
    Journal of Statistical Mechanics: Theory and Experiment, Jan. 2020, [Reviewed]
  • Global Thermodynamics for Heat Conduction Systems
    Nakagawa, Naoko; Sasa, Shin-ichi, Lead, We propose the concept of global temperature for spatially non-uniform heat conduction systems. With this novel quantity, we present an extended framework of thermodynamics for the whole system such that the fundamental relation of thermodynamics holds, which we call "global thermodynamics" for heat conduction systems. Associated with this global thermodynamics, we formulate a variational principle for determining thermodynamic properties of the liquid-gas phase coexistence in heat conduction, which corresponds to the natural extension of the Maxwell construction for equilibrium systems. We quantitatively predict that the temperature of the liquid-gas interface deviates from the equilibrium transition temperature. This result indicates that a super-cooled gas stably appears near the interface., SPRINGER
    JOURNAL OF STATISTICAL PHYSICS, Dec. 2019, [Reviewed]
  • Unattainability of Carnot efficiency in thermal motors: Coarse graining and entropy production of Feynman-Smoluchowski ratchets
    Nakayama, Y.; Kawaguchi, K.; Nakagawa, N., Corresponding
    Physical Review E, Aug. 2018, [Reviewed]
  • Liquid-Gas Transitions in Steady Heat Conduction
    Naoko Nakagawa; Shin-ichi Sasa, Lead, We study liquid-gas transitions of heat conduction systems in contact with two heat baths under constant pressure in the linear response regime. On the basis of local equilibrium thermodynamics, we propose an equality with a global temperature, which determines the volume near the equilibrium liquid- gas transition. We find that the formation of the liquid- gas interface is accompanied by a discontinuous change in the volume when increasing the mean temperature of the baths. A supercooled gas near the interface is observed as a stable steady state., AMER PHYSICAL SOC
    PHYSICAL REVIEW LETTERS, Dec. 2017, [Reviewed]
  • Numerical determination of entropy associated with excess heat in steady-state thermodynamics
    Yoshiyuki Chiba; Naoko Nakagawa, Last, We numerically determine the global entropy for heat-conducting states, which is connected to the so-called excess heat considered as a basic quantity for steady-state thermodynamics in nonequilibrium. We adopt an efficient method to estimate the global entropy from the bare heat current and find that the obtained entropy agrees with the familiar local equilibrium hypothesis well. Our method possesses a wider applicability than local equilibrium and opens a possibility to compare thermodynamic properties of complex systems in nonequilibrium with those in the local equilibrium. We further investigate the global entropy for heat-conducting states and find that it exhibits both extensive and additive properties; however, the two properties do not degenerate each other differently from those at equilibrium. The separation of the extensivity and additivity makes it difficult to apply powerful thermodynamic methods to the nonequilibrium steady states., AMER PHYSICAL SOC
    PHYSICAL REVIEW E, Aug. 2016, [Reviewed]
  • Steady State Thermodynamics based on Local Equilibrium Hypothesis
    Nakagawa Naoko; Sasa Shin-ichi,

    非平衡定常系の一例として熱伝導系を取り上げる。局所熱力学量をもとに適切に大域熱力学量を定義すると、ギブス関係式などの諸関係式が成立することを報告する。過剰エントロピー生成により決定される非平衡エントロピーとの関係についても述べる。

    , The Physical Society of Japan
    Meeting Abstracts of the Physical Society of Japan, 2016
  • Exact Equalities and Thermodynamic Relations for Nonequilibrium Steady States
    Teruhisa S. Komatsu; Naoko Nakagawa; Shin-ichi Sasa; Hal Tasaki, We study thermodynamic operations which bring a nonequilibrium steady state (NESS) to another NESS in physical systems under nonequilibrium conditions. We model the system by a suitable Markov jump process, and treat thermodynamic operations as protocols according to which the external agent varies parameters of the Markov process. Then we prove, among other relations, a NESS version of the Jarzynski equality and the extended Clausius relation. The latter can be a starting point of thermodynamics for NESS. We also find that the corresponding nonequilibrium entropy has a microscopic representation in terms of symmetrized Shannon entropy in systems where the microscopic description of states involves "momenta". All the results in the present paper are mathematically rigorous., SPRINGER
    JOURNAL OF STATISTICAL PHYSICS, Jun. 2015, [Reviewed]
  • Universal expression for adiabatic pumping in terms of nonequilibrium steady states
    Naoko Nakagawa, Lead, We develop a unified treatment of pumping and nonequilibrium thermodynamics. We show that the pumping current generated through an adiabatic mechanical operation in equilibrium can be expressed in terms of the stationary distribution of the corresponding driven nonequilibrium system. We also show that the total transfer in pumping can be evaluated from the work imported to the driven counterpart. These findings lead us to a unified viewpoint for pumping and nonequilibrium thermodynamics., AMER PHYSICAL SOC
    PHYSICAL REVIEW E, Aug. 2014, [Reviewed]
  • Characterization of the low-temperature properties of a simplified protein model
    Johannes-Geert Hagmann; Naoko Nakagawa; Michel Peyrard, Prompted by results that showed that a simple protein model, the frustrated Go model, appears to exhibit a transition reminiscent of the protein dynamical transition, we examine the validity of this model to describe the low-temperature properties of proteins. First, we examine equilibrium fluctuations. We calculate its incoherent neutron-scattering structure factor and show that it can be well described by a theory using the one-phonon approximation. By performing an inherent structure analysis, we assess the transitions among energy states at low temperatures. Then, we examine nonequilibrium fluctuations after a sudden cooling of the protein. We investigate the violation of the fluctuation-dissipation theorem in order to analyze the protein glass transition. We find that the effective temperature of the quenched protein deviates from the temperature of the thermostat, however it relaxes towards the actual temperature with an Arrhenius behavior as the waiting time increases. These results of the equilibrium and nonequilibrium studies converge to the conclusion that the apparent dynamical transition of this coarse-grained model cannot be attributed to a glassy behavior., AMER PHYSICAL SOC
    PHYSICAL REVIEW E, Jan. 2014, [Reviewed]
  • Work relations for time-dependent states
    Naoko Nakagawa; Shin-ichi Sasa, Lead, For time-dependent states generated by an external operation, a generalized free energy may be introduced by the relative entropy with respect to an equilibrium state realized after sufficient relaxation from the time-dependent states. Recently, by studying overdamped systems, Sivak and Crooks presented a formula that relates the generalized free energy with measurable thermodynamic works. We rederive this relation with emphasizing a connection to an extended Clausius relation proposed in the framework of steady state thermodynamics. As a natural consequence, we generalize this relation to be valid for systems with momentum degrees of freedom, where the Shannon entropy in the generalized free energy is replaced by a symmetric one. DOI: 10.1103/PhysRevE.87.022109, AMER PHYSICAL SOC
    PHYSICAL REVIEW E, Feb. 2013, [Reviewed]
  • Work relation and the second law of thermodynamics in nonequilibrium steady states
    Naoko Nakagawa, Lead, We extend Jarzynski's work relation and the second law of thermodynamics to a heat conducting system, which is operated by an external agent. These extensions contain a nonequilibrium contribution expressed as the violation of the (linear) response relation caused by the operation. We find that a natural extension of the minimum work principle involves information about the time-reversed operation, and is far from straightforward. Our work relation may be tested experimentally especially when the temperature gradient is small., AMER PHYSICAL SOC
    PHYSICAL REVIEW E, May 2012, [Reviewed]
  • Entropy and Nonlinear Nonequilibrium Thermodynamic Relation for Heat Conducting Steady States
    Teruhisa S. Komatsu; Naoko Nakagawa; Shin-ichi Sasa; Hal Tasaki, Corresponding, Among various possible routes to extend entropy and thermodynamics to nonequilibrium steady states (NESS), we take the one which is guided by operational thermodynamics and the Clausius relation. In our previous study, we derived the extended Clausius relation for NESS, where the heat in the original relation is replaced by its "renormalized" counterpart called the excess heat, and the Gibbs-Shannon expression for the entropy by a new symmetrized Gibbs-Shannon-like expression. Here we concentrate on Markov processes describing heat conducting systems, and develop a new method for deriving thermodynamic relations. We first present a new simpler derivation of the extended Clausius relation, and clarify its close relation with the linear response theory. We then derive a new improved extended Clausius relation with a "nonlinear nonequilibrium" contribution which is written as a correlation between work and heat. We argue that the "nonlinear nonequilibrium" contribution is unavoidable, and is determined uniquely once we accept the (very natural) definition of the excess heat. Moreover it turns out that to operationally determine the difference in the nonequilibrium entropy to the second order in the temperature difference, one may only use the previous Clausius relation without a nonlinear term or must use the new relation, depending on the operation (i.e., the path in the parameter space). This peculiar "twist" may be a clue to a better understanding of thermodynamics and statistical mechanics of NESS., SPRINGER
    JOURNAL OF STATISTICAL PHYSICS, Jan. 2011, [Reviewed]
  • Stationary Distribution and Thermodynamic Relation in Nonequilibrium Steady States
    Teruhisa S. Komatsu; Naoko Nakagawa; Shin-ichi Sasa; Hal Tasaki; Nobuyasu Ito, We describe our recent attempts toward statistical mechanics and thermodynamics for nonequilibrium steady states (NESS) realized, e.g., in a heat conducting system. Our first result is a simple expression of the probability distribution (of microscopic states) of a NESS. Our second result is a natural extension of the thermodynamic Clausius relation and a definition of an accompanying entropy in NESS. This entropy coincides with the normalization constant appearing in the above mentioned microscopic expression of NESS, and has an expression similar to the Shannon entropy (with a further symmetrization). The NESS entropy proposed here is a clearly defined measurable quantity even in a system with a large degrees of freedom. We numerically measure the NESS entropy in hardsphere fluid systems with a heat current, by observing energy exchange between the system and the heat baths when the temperatures of the baths are changed according to specified protocols., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE
    PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 2010, [Reviewed], [Invited]
  • Critical examination of the inherent-structure-landscape analysis of two-state folding proteins
    Johannes-Geert Hagmann; Naoko Nakagawa; Michel Peyrard, Recent studies attracted the attention on the inherent-structure-landscape (ISL) approach as a reduced description of proteins allowing to map their full thermodynamic properties. However, the analysis has been so far limited to a single topology of a two-state folding protein, and the simplifying assumptions of the method have not been examined. In this work, we construct the thermodynamics of four two-state folding proteins of different sizes and secondary structure by molecular dynamics (MD) simulations using the ISL method and critically examine possible limitations of the method. Our results show that the ISL approach correctly describes the thermodynamics function, such as the specific heat, on a qualitative level. Using both analytical and numerical methods, we show that some quantitative limitations cannot be overcome with enhanced sampling or the inclusion of harmonic corrections., AMER PHYSICAL SOC
    PHYSICAL REVIEW E, Dec. 2009, [Reviewed]
  • Representation of Nonequilibrium Steady States in Large Mechanical Systems
    Teruhisa S. Komatsu; Naoko Nakagawa; Shin-Ichi Sasa; Hal Tasaki, Recently a novel concise representation of the probability distribution of heat conducting nonequilibrium steady states was derived. The representation is valid to the second order in the "degree of nonequilibrium", and has a very suggestive form where the effective Hamiltonian is determined by the excess entropy production. Here we extend the representation to a wide class of nonequilibrium steady states realized in classical mechanical systems where baths (reservoirs) are also defined in terms of deterministic mechanics. The present extension covers such nonequilibrium steady states with a heat conduction, with particle flow (maintained either by external field or by particle reservoirs), and under an oscillating external field. We also simplify the derivation and discuss the corresponding representation to the full order., SPRINGER
    JOURNAL OF STATISTICAL PHYSICS, Jan. 2009, [Reviewed]
  • Steady-state thermodynamics for heat conduction: Microscopic derivation
    Teruhisa S. Komatsu; Naoko Nakagawa; Shin-ichi Sasa; Hal Tasaki, Starting from microscopic mechanics, we derive thermodynamic relations for heat conducting nonequilibrium steady states. The extended Clausius relation enables one to experimentally determine nonequilibrium entropy to the second order in the heat current. The associated Shannon-like microscopic expression of the entropy is suggestive. When the heat current is fixed, the extended Gibbs relation provides a unified treatment of thermodynamic forces in the linear nonequilibrium regime., AMER PHYSICAL SOC
    PHYSICAL REVIEW LETTERS, Jun. 2008, [Reviewed]
  • Expression for the stationary distribution in nonequilibrium steady states
    Teruhisa S. Komatsu; Naoko Nakagawa, Last, We study the nonequilibrium steady state realized in a general stochastic system attached to multiple heat baths. Starting from the detailed fluctuation theorem, we derive concise and suggestive expressions for the corresponding stationary distribution which are correct up to the second order in thermodynamic forces. The probability of a microstate eta is proportional to exp[Phi(eta)] where Phi(eta)=-Sigma(k)beta(k)E(k)(eta) is the excess entropy change. Here, E(k)(eta) is the difference between two kinds of conditioned path ensemble averages of excess heat transfer from the kth heat bath whose inverse temperature is beta(k). This result can be easily extended to steady states maintained with other sources, e.g., particle current driven by an external force. Our expression may be verified experimentally in nonequilibrium states realized, for example, in mesoscopic systems., AMER PHYSICAL SOC
    PHYSICAL REVIEW LETTERS, Jan. 2008, [Reviewed]
  • Conformational temperature characterizing the folding of a protein
    Naoko Nakagawa, Lead, The time sequences of the molecular dynamics simulation for the folding process of a protein is analyzed with the inherent structure landscape which focuses on the configurational dynamics of the system. Time-dependent energy and entropy for inherent structures are introduced, and from these quantities a conformational temperature is defined. The conformational temperature follows the time evolution of a slow relaxation process and reaches the bath temperature when the system is equilibrated. We show that the nonequilibrium system is described by two temperatures, one for fast vibration and the other for slow configurational relaxation, while the equilibrium system is described by one temperature. The proposed formalism is applicable widely for systems with many metastable states., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW LETTERS, Mar. 2007, [Reviewed]
  • A reversibility parameter for a Markovian stepper
    T. Harada; N. Nakagawa, Last, Recent experimental studies on the stepwize motion of biological molecular motors have revealed that the "characteristic distance" of a step is usually less than the actual step size. This observation implies that the detailed-balance condition for kinetic rates of steps is violated in these motors. In this letter, in order to clarify the significance of the characteristic distance, we study a Langevin model of a molecular motor with a hidden degree of freedom. We find that the ratio of the characteristic distance to the step size is equal to unity if the dominant paths in the state space are one-dimensional, while it deviates from unity if the dominant paths are branched. Therefore, this parameter can be utilized to determine the reversibility of a motor even under a restricted observation. Copyright (C) EPLA, 2007., EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY
    EPL, 2007, [Reviewed]
  • Modeling protein thermodynamics and fluctuations at the mesoscale
    Naoko Nakagawa; Michel Peyrard, Lead, We use an extended G (o) over bar model, in unfrustrated and frustrated variants, to study the energy landscape and the fluctuations of a model protein. The model exhibits two transitions, folding and dynamical transitions, when changing the temperature. The inherent structures corresponding to the minima of the landscape are analyzed and we show how their energy density can be obtained from simulations around the folding temperature. The scaling of this energy density is found to reflect the folding transition. Moreover, this approach allows us to build a reduced thermodynamics in the inherent structure landscape. Equilibrium studies, from full molecular dynamics (MD) simulations and from the reduced thermodynamics, detect the features of a dynamical transition at low temperature and we analyze the location and time scale of the fluctuations of the protein, showing the need of some frustration in the model to get realistic results. The frustrated model also shows the presence of a kinetic trap which strongly affects the dynamics of folding., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW E, Oct. 2006, [Reviewed]
  • Dynamical regulation of transition states resulting from heat flow
    Naoko Nakagawa; Teruhisa S. Komatsu, Lead, Under a non-equilibrium steady state, an oriented motion of a particle on a one-dimensional flexible rail composed of a line with multiple binding sites of the particle is studied. The dynamical coupling among the particle and the sites allows the system's configuration to fluctuate rather flexibly. Our study focuses on the transition states for the change of the binding site. Due to the flexibility of the system, the transition states at non-equilibrium are found to deviate from those at equilibrium. The excess energy absorbed by the system from the heat baths to attain the transition states is also evaluated. These results consistently account the direction of the oriented motion., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE
    Progress of Theoretical Physics Supplment, Aug. 2006, [Reviewed]
  • A heat pump at a molecular scale controlled by a mechanical force
    Naoko Nakagawa; Teruhisa S. Komatsu, Lead, We show that a mesoscopic system such as Feynman's ratchet may operate as a heat pump, and clarify underlying physical picture. We consider a system of a particle moving along an asymmetric periodic structure. When put into contact with two distinct heat baths of equal temperature, the system transfers heat between two baths as the particle is dragged. We examine Onsager relation for the heat flow and the particle flow, and show that the reciprocity coefficient is a product of the characteristic heat and the diffusion constant of the particle. The characteristic heat is the heat transfer between the baths associated with a barrier-overcoming process. Because of the correlation between the heat flow and the particle flow, the system can work as a heat pump when the particle is dragged. This pump is particularly effective at molecular scales where the energy barrier is of the order of the thermal energy., EDP SCIENCES S A
    EUROPHYSICS LETTERS, Jul. 2006, [Reviewed]
  • Hidden heat transfer in equilibrium states implies directed motion in nonequilibrium states
    Teruhisa S. Komatsu; Naoko Nakagawa, Last, We study a class of heat engines including Feynman's ratchet, which exhibits a directed motion of a particle in nonequilibrium steady states maintained by two heat baths. We measure heat transfer from each heat bath separately, and average them using a careful procedure that reveals the nature of the heat transfer associated with directed steps of the particle. Remarkably we find that steps are associated with nonvanishing heat transfer even in equilibrium, and there is a quantitative relation between this hidden heat transfer and the directed motion of the particle. This relation is clearly understood in terms of the principle of heat transfer enhancement, which is expected to apply to a large class of highly nonequilibrium systems., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW E, Jun. 2006, [Reviewed]
  • The inherent structure landscape of a protein
    N Nakagawa; M Peyrard, Using the Go model of a real protein, we explore the landscape of its metastable structures. First, we show how the inherent structure energy density can be obtained from the probability density determined by sampling molecular dynamics trajectories and quenching. The analysis of the inherent structure landscape can characterize the folding transition. Then we show how thermodynamics of the inherent states can be established to study the equilibrium properties of proteins. Our work brings some elements into the current discussion about the protein dynamical transition. The study uses a simplified model to illustrate the ideas, but, as the inherent structure landscape is much simpler than the free energy surface of the protein, it appears to be accessible for an all-atom model of a small protein, at the expense of much longer calculations., NATL ACAD SCIENCES
    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Apr. 2006, [Reviewed]
  • Dynamically regulated energy barriers with violation of symmetry for reaction path
    Nakagawa, N.; Komatsu, T.S., Lead
    Physica A: Statistical Mechanics and its Applications, Jan. 2006, [Reviewed]
  • An oriented process induced by dynamically regulated energy barriers
    Naoko Nakagawa; Teruhisa S. Komatsu, Lead, A novel mechanism for inducing oriented processes is investigated with a flexible system exhibiting barrier-overcoming dynamics. Without any external switching of potentials, multidimensional flexible dynamics promote the oriented processes under nonequilibrium conditions, where reaction paths deviate from those at equilibrium with an accompanying violation of symmetry between the forward and the reverse paths. Along each path, distinct bottleneck points are proposed as a rate-controlling factor. The direction-dependent activation energies evaluated from the actual potential energies at these points are found to satisfy Arrhenius-like law for the rate constants., PHYSICAL SOC JAPAN
    Journal of Physical Society Japan, Jun. 2005, [Reviewed]
  • Autonomous Energy Transducer : Proposition, Example, Basic Characteristics
    Naoko Nakagawa; Kunihiko Kaneko, Lead, We propose a concept of autonomous energy transducer at a molecular scale, where output is produced with small input energy, not very much larger than the thermal energy, without restriction of magnitude or timing of input, and without any control after the input. As an example that satisfies these requisites, a dynamical systems model with several degrees of freedom is proposed, which transduces input energy to output motion on the average. It is shown that this transduction is robust and the coupling between input and output is generally loose. How this transducer works is analyzed in terms of dynamical systems theory, where chaotic dynamics of the internal degrees of freedom, as well as duration of excited conformation of an active part which is self-organized with the energy flow, is essential. We also discuss possible relationships to enzyme dynamics or protein motors. (C) 2004 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
    Physica A, 2004, [Reviewed]
  • Dynamical mechanism for the conversion of energy at a molecular scale
    Naoko Nakagawa; Kunihiko Kaneko, A dynamical mechanism of a molecular machine for energy conversion, by considering a simple model describing the dynamics of the head and the chain is proposed. In the mechanism, after the injection of energy to the head region, the energy is stored at one part for some time, and is used step by step, allowing the head to move diretionally along the chain. The numerical simulations demonstrate that a directional motion is extracted, among all the degrees of the system, even though input is not specifically controlled with regards to its timing or direction.
    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, Apr. 2003
  • Energy Conversion by Autonomous Regulation of Chaos: Dynamical Mechanism of Loose Coupling
    Naoko Nakagawa; Kunihiko Kaneko; Teruhisa S.Komatsu, Lead, Inspired by recent experiments of molecular motors, a dynamical systems model for a flexible machine is proposed which converts injected energy to output directional motion. The output amount is distributed broadly, and thus the coupling between input energy and output motion is loose, as in the experiments. This energy conversion is shown to be robust against the change of surrounding environment. Stability analysis on the fixed point solutions of the model is presented, which suggests that transient chaotic motion, induced by temporal three-body motion, is relevant to the energy conversion. (C) 2003 American Institute of Physics., AMER INST PHYSICS
    Chaos, 2003, [Reviewed], [Invited]
  • Dynamical Mechanism for the Conversion of Energy at a Molecular Scale
    Naoko Nakagawa; Kunihiko Kaneko, Lead, We propose a dynamical mechanism of a molecular machine for energy conversion, by considering a simple model describing the dynamics of two components, the head and the chain. After injection of energy to the head region, the energy is stored at one part for some time, and is used step by step, allowing the head to move directionally along the chain, irrespective of the direction of the input, under a fluctuating environment. Our system can adjust the timing with which the head crosses the energy barrier by taking advantage of internal dynamics and the flexibility of components. Some suggestions are given for molecular machines., AMER PHYSICAL SOC
    Physical Review E, 2003, [Reviewed]
  • Creep motion in a granular pile exhibiting steady surface flow
    TS Komatsu; S Inagaki; N Nakagawa; S Nasuno, We investigate experimentally granular piles exhibiting steady surface flow. Below the surface how, it has been believed that a "frozen" bulk region exists, but our results show no such frozen bulk. We report here that even the particles in layers deep in the bulk exhibit very slow flow and that such motion can be detected at an arbitrary depth, The mean velocity of the creep motion decays exponentially with depth, and the characteristic decay length is approximately equal to the particle size and is independent of the flow rare. It is expected that the creep motion we have seen is observable in all sheared granular systems., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW LETTERS, Feb. 2001, [Reviewed]
  • Relaxation, the Boltzmann-Jeans Conjecture and Chaos
    Naoko Nakagawa; Kunihiko Kaneko, Lead, Slow (logarithmic) relaxation from a highly excited state is studied in a Hamiltonian system with many degrees of freedom. The relaxation time is shown to increase as the exponential of the square root of the energy of excitation, in agreement with the Boltzmann-Jeans conjecture. while it is found to be inversely proportional to residual Kolmogorov-Sinai entropy, introduced in this Rapid Communication. The increase of the thermodynamic entropy through this relaxation process is found to be proportional to this quantity., AMER PHYSICAL SOC
    Physical Review E, 2001, [Reviewed]
  • Long-term Relaxation of a Composite System in Partial Contact with a Heat Bath
    Naoko Nakagawa; Kunihiko Kaneko; Teruhisa S. Komatsu, Lead, We study relaxational behavior from a highly excited state for a composite system in partial contact with a heat bath, motivated by an experimental report of long-term energy storage in protein molecules. The system consists of two coupled elements: The first element is in direct contact with a heat bath, while the second element interacts only with the first element, Due to this indirect contact with the heat bath, energy injected into the second element dissipates very slowly, according to a power law, whereas that injected into the first one exhibits exponential dissipation. The relaxation equation describing this dissipation is obtained analytically for both the underdamped and overdamped limits. Numerical confirmation is given for both cases., PHYSICAL SOC JAPAN
    Journal of Physical Society Japan, 2000, [Reviewed]
  • Energy Storage in a Hamiltonian System in Partial Contact with a Heat Bath
    Naoko Nakagawa; Kunihiko Kaneko, Lead, To understand the mechanism allowing for the long-term storage of excess energy in proteins, we study a Hamiltonian system consisting of several coupled pendula in partial contact with a heat bath. It is found that energy storage is possible when the motion of each pendulum switches between oscillatory (vibrational) and rotational (phase-slip) modes. The storage time increases almost exponentially to the square root of the injected energy. The relevance of our mechanism to protein motors is discussed., PHYSICAL SOC JAPAN
    Journal of Physical Society Japan, 2000, [Reviewed]
  • Confined chaotic behavior in collective motion for populations of globally coupled chaotic elements
    N Nakagawa; TS Komatsu, Lead, The Lyapunov exponent for collective motion is defined in order to characterize chaotic properties of collective motion for large populations of chaotic elements. Numerical computations for this quantity suggest that such collective motion is always chaotic, whenever it appears. Chaotic behavior of collective motion is found to be confined within a small scale, whose size is estimated using the value of the Lyapunov exponent. Finally, we conjecture why the collective motion appears low dimensional despite the actual high dimensionality of the dynamics. [S1063-651X(99)06802-6]., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW E, Feb. 1999, [Reviewed]
  • Collective motion occurs inevitably in a class of populations of globally coupled chaotic elements
    N Nakagawa; TS Komatsu, Lead, We discovered numerically a scaling law obeyed by the amplitude of collective motion in large populations of chaotic elements. Our analysis strongly suggests that such populations generically exhibit collective motion in the presence of interaction, however weak it may be. A phase diagram for the collective motion, which is characterized by peculiar structures similar to Arnold tongues, is obtained. [S1063-651X(98)06502-7]., AMERICAN PHYSICAL SOC
    PHYSICAL REVIEW E, Feb. 1998, [Reviewed]
  • ANOMALOUS LYAPUNOV SPECTRUM IN GLOBALLY COUPLED OSCILLATORS
    N NAKAGAWA; Y KURAMOTO, Lead, Numerical experiments of a globally coupled oscillator system show that one type of collective chaos of high dimension has discrete and continuous parts in its Lyapunov spectrum. This occurs in a scattered state, i.e., a state in which no two oscillators behave identically. It is argued from a consideration of the phase space structure that the discrete exponents are related to, in a sense, the macroscopic dynamics, while the continuous part reflects the microscopic dynamics. This type of high-dimensional chaos is compared to a second type possessing an apparently continuous part only. Preceding the appearance of the first type, we found a sequence of bifurcations of collective low-dimensional behavior in scattered states, and their investigation reveals the route to the first type of the high-dimensional chaos., ELSEVIER SCIENCE BV
    PHYSICA D, Jan. 1995, [Reviewed]
  • FROM COLLECTIVE OSCILLATIONS TO COLLECTIVE CHAOS IN A GLOBALLY COUPLED OSCILLATOR SYSTEM
    N NAKAGAWA; Y KURAMOTO, Lead, Various types of collective behaviors are discovered in globally coupled Ginzburg-Landau oscillators. When the coupling is sufficiently weak, the oscillators are either in complete synchrony or their phases are scattered completely randomly. For finite coupling, new collective behaviors emerge such as splitting of the population into a small number of clusters or their fusion into a continuous stringlike distribution in the phase plane. Low-dimensional chaotic dynamics arises from the coupled motion of 3 point-clusters. Chaotic motion is also exhibited by fused clusters which is of extremely high dimension possibly proportional to the system size as is implied from its Lyapunov analysis. In the latter type of chaos, the motion of the string is in some cases characterized by repeated stretching-and-foldings. It is argued how this kind of coherent behavior seen on a collective level does not contradict the high dimensionality of the corresponding chaotic attractor., ELSEVIER SCIENCE BV
    PHYSICA D, Aug. 1994, [Reviewed]
  • COLLECTIVE CHAOS IN A POPULATION OF GLOBALLY COUPLED OSCILLATORS
    N NAKAGAWA; Y KURAMOTO, Lead, Different forms of collective chaos are found in a large population of globally coupled identical oscillators of the complex Ginzburg-Landau type. Under certain conditions, the entire population splits into three point-clusters, and their coupled dynamics generates chaos of low dimension. It also occurs that all these clusters are fused into one continuous distribution in the form of a closed loop. This object exhibits stretching-and-folding behavior characteristic to chaos, whose interpretation is provided from the approximate equivalence of our system to an ensemble of independent oscillators driven by a common periodic field. It is found that collective chaos also arises when fused and point clusters coexist., KYOTO UNIV
    PROGRESS OF THEORETICAL PHYSICS, Feb. 1993, [Reviewed]

MISC

Lectures, oral presentations, etc.

  • Measurement of temperature distribution and pressure in gas-liquid phase coexisting system under heat conduction　　　　　　　　　　　　　　　
    R. Higa; F. Kagawa; N. Nakagawa; S. Sasa
    日本物理学会 2025年春季大会, 19 Mar. 2025
    20250318, 20250321
  • Global Thermodynamics for Heat Conduction Systems　　　　　　　　　　　　　　　
    Naoko Nakagawa
    理研 iTHEMS セミナー, 02 Dec. 2024, [Invited]
  • 弱い熱流がもたらす準安定状態の定常化：非一様系を粗く捉える大域熱力学の現象予測力とその検証　　　　　　　　　　　　　　　
    中川尚子
    大阪公立大学 大学院理学研究科 物理学専攻 談話会, 13 Nov. 2024, [Invited]
  • Collective dynamics and effective number of molecules in dissociable diatomic molecular systems　　　　　　　　　　　　　　　
    Takehiro Kanazawa; Takenobu Nakamura; Naoko Nakagawa
    日本物理学会 第79回年次大会, 18 Sep. 2024
  • Equilibrium correspondence of heat conduction systems in global thermodynamics　　　　　　　　　　　　　　　
    Naoko Nakagawa; Shin-ichi Sasa
    日本物理学会 第79回年次大会, 18 Sep. 2024
  • Mesoscopic dynamics of liquid-gas coexistence in heat conduction systems　　　　　　　　　　　　　　　
    Akira Yoshida; Naoko Nakagawa; Shin-ichi Sasa
    日本物理学会 第79回年次大会, 18 Sep. 2024
  • Mesoscopic dynamics of phase coexistence in boundary driven diffusive systems　　　　　　　　　　　　　　　
    Shin-ichi Sasa; Naoko Nakagawa; Akira Yoshda
    日本物理学会 第79回年次大会, 18 Sep. 2024
  • Configuration in liquid-gas coexistence resulted from wettability of walls　　　　　　　　　　　　　　　
    Yuki Nakamura; Naoko Nakagawa
    日本物理学会 第79回年次大会, 17 Sep. 2024
  • グローバルで行こう! – 非平衡視点の熱力学再検討がもたらす大域熱力学 –　　　　　　　　　　　　　　　
    中川尚子
    第69回 物性若手夏の学校, 05 Aug. 2024, [Invited]
  • 大域熱力学これまで・これから　　　　　　　　　　　　　　　
    中川尚子
    非平衡系の物理, 25 Mar. 2024, [Invited]
    20240325, 20240326
  • 重力下熱伝導気液共存系における熱力学的安定性　　　　　　　　　　　　　　　
    吉田旭; 中川尚子; 佐々真一
    日本物理学会, 19 Mar. 2024
    20240318, 20240321
  • マイクロバブルの生成に起因する熱力学量変化　　　　　　　　　　　　　　　
    仲村友希; 中川尚子
    日本物理学会, 18 Mar. 2024
    20240318, 20240321
  • 古典二原子分子の分子状態ゆらぎを特徴づける自由エネルギーの探索　　　　　　　　　　　　　　　
    金澤広大; 中川尚子
    日本物理学会, 18 Mar. 2024
    20240318, 20240321
  • １次元外力駆動粒子系における相共存と大域熱力学　　　　　　　　　　　　　　　
    佐々真一; 中川尚子
    第１１回ソフトマター研究会, 19 Dec. 2023
    20231218, 20231220
  • 重力で沈んだ液体の熱流による浮上　　　　　　　　　　　　　　　
    吉田旭; 中川尚子; 佐々真一
    第１１回ソフトマター研究会, 19 Dec. 2023
    20231218, 20231220
  • 大域熱力学：非平衡相共存の粗視化による定量的予測　　　　　　　　　　　　　　　
    中川尚子
    第１１回ソフトマター研究会, 19 Dec. 2023, [Invited]
    20231218, 20231220
  • 簡単な相互作用粒子モデルによる大域熱力学の数値的検討　　　　　　　　　　　　　　　
    佐々真一; 中川尚子
    日本物理学会, 17 Sep. 2023
    20230916, 20230919
  • 分子の解離可能性の有無による自由エネルギーの差　　　　　　　　　　　　　　　
    吉田旭; 平野菜奈子; 中村壮伸; 中川尚子
    日本物理学会, 17 Sep. 2023
    20230916, 20230919
  • 重力下に置かれた流体の大域熱力学的構造　　　　　　　　　　　　　　　
    中川尚子; 佐々真一
    日本物理学会, 17 Sep. 2023
    20230916, 20230919
  • Work relation for determining the mixing free energy of small-scale mixtures　　　　　　　　　　　　　　　
    Akira Yoshida; Naoko Nakagawa
    STATPHYS28, 08 Aug. 2023
    20230807, 20230811
  • Global thermodynamics for heat conduction systems　　　　　　　　　　　　　　　
    Naoko Nakagawa
    STATPHYS28, 07 Aug. 2023
    20230807, 20230811
  • 混ぜる自由エネルギーと分ける自由エネルギー　　　　　　　　　　　　　　　
    中川尚子
    第10回統計物理学懇談会, 28 Mar. 2023, [Invited]
    20230327, 20230328
  • 重力と熱流がもたらす非自明な相配置と必然的な準安定状態2　　　　　　　　　　　　　　　
    吉田旭、中川尚子、佐々真一
    日本物理学会, 22 Mar. 2023
    20230322, 20230325
  • Global thermodynamics for heat conduction systems　　　　　　　　　　　　　　　
    Naoko Nakagawa
    Japan-France joint seminar "Physics of dense and active disordered materials", 16 Mar. 2023, 京都大学基礎物理学研究所, [Invited]
    20230313, 20230316
  • 大域熱力学と熱伝導下相共存　　　　　　　　　　　　　　　
    中川尚子
    新潟大学物理教室コロキウム, 10 Nov. 2022, [Invited]
    20221110
  • 層流と気液界面を共存させる条件　　　　　　　　　　　　　　　
    中川尚子、佐々真一
    日本物理学会, 13 Sep. 2022
    20220912, 20220915
  • ゆらぐ系から創発するカオス　　　　　　　　　　　　　　　
    佐々真一、中川尚子
    日本物理学会, 13 Sep. 2022
    20220912, 20220915
  • 重力と熱流がもたらす非自明な相配置と必然的な準安定状態　　　　　　　　　　　　　　　
    吉田旭、中川尚子、佐々真一
    日本物理学会, 13 Sep. 2022
    20220912, 20220915
  • Global thermodynamics for heat conduction states : 非平衡状態を粗っぽく見る枠組みの提案　　　　　　　　　　　　　　　
    中川尚子
    ISSPワークショップ 開放系トポロジーと生体・量子・統計物理, 28 Mar. 2022, 岡 隆史, [Invited]
    20220328, 20220330
  • 混合自由エネルギーによる二成分流体気液転移の有限サイズ効果の特徴付け　　　　　　　　　　　　　　　
    吉田旭; 中川尚子
    日本物理学会, 17 Mar. 2022
    20220315, 20220319
  • 熱流による気液界面の安定化と界面近傍状態の再現の難しさ　　　　　　　　　　　　　　　
    加村優悟; 中川尚子
    日本物理学会, 17 Mar. 2022
    20220315, 20220319
  • 熱流下気液相共存系に関する局所温度・気相圧力計測の実験　　　　　　　　　　　　　　　
    久田淳司,賀川史敬,中川尚子; 佐々真一
    日本物理学会, 17 Mar. 2022
    20220315, 20220319
  • 準静的分割の構成とギブスのパラドックス　　　　　　　　　　　　　　　
    佐々真一; 日浦健; 中川尚子; 吉田旭
    日本物理学会, 16 Mar. 2022
    20220315, 20220319
  • 格子気体非平衡相共存についての大域熱力学　　　　　　　　　　　　　　　
    中川尚子; 佐々真一
    日本物理学会, 23 Sep. 2021
    20210920, 20210923
  • 格子気体非平衡相共存におけるゆらぎのポテンシャル　　　　　　　　　　　　　　　
    佐々真一; 中川尚子
    日本物理学会, 23 Sep. 2021
    20210920, 20210923
  • 錬金術法による操作仕事を用いた活量係数の表式　　　　　　　　　　　　　　　
    吉田旭; 中川尚子
    日本物理学会, 23 Sep. 2021
    20210920, 20210923
  • レナード=ジョーンズ粒子系の気液界面付近における熱 伝導率変化　　　　　　　　　　　　　　　
    加村優悟; 中川尚子
    日本物理学会, 21 Sep. 2021
    20210920, 20210923
  • Global thermodynamics for heat conduction states　　　　　　　　　　　　　　　
    中川尚子
    中央大学・素粒子理論研究室セミナー, 05 Jul. 2021, [Invited]
  • 非相加的エントロピーで体系化される大域熱力学　　　　　　　　　　　　　　　
    中川尚子; 佐々真一
    日本物理学会, 14 Mar. 2021
    20210312, 20210315
  • ハミルトン・ポッツ模型を用いた一次相転移 界面を含む熱伝導状態の解析　　　　　　　　　　　　　　　
    小林未知数; 中川尚子; 佐々真一
    日本物理学会, 14 Mar. 2021
    20210312, 20210315
  • 熱伝導下にある二成分流体を大域的に記述する熱力学の構 築　　　　　　　　　　　　　　　
    吉田旭; 中川尚子
    日本物理学会, 13 Mar. 2021
    20210312, 20210315
  • 斥力相互作用するアクティブブラウン粒子における相分離の熱力学量による特徴づけ　　　　　　　　　　　　　　　
    村上千佳; 中川尚子
    日本物理学会, 10 Sep. 2020
    20200908, 20200911
  • ポワズイユ流下での気液界面温度特異性を決める無次元パラメータ　　　　　　　　　　　　　　　
    中川尚子; 佐々真一
    日本物理学会, 08 Sep. 2020
    20200908, 20200911
  • ゆらぐ相境界ダイナミクスに対する熱流効果　　　　　　　　　　　　　　　
    佐々真一; 中川尚子
    日本物理学会, 08 Sep. 2020
    20200908, 20200911
  • Lennard-Jones熱伝導系における気液転移　　　　　　　　　　　　　　　
    湯川諭; 中川尚子; 佐々真一
    日本物理学会, 08 Sep. 2020
    20200908, 20200911
  • 多成分系を大域的に記述する熱力学関数の決定　　　　　　　　　　　　　　　
    吉田旭; 中川尚子
    日本物理学会, 08 Sep. 2020
    20200908, 20200911
  • 蔵本モデルでの非平衡エントロピー測定とその精度問題　　　　　　　　　　　　　　　
    高野晃太郎; 中川尚子
    日本物理学会, 08 Sep. 2020
    20200908, 20200911

Affiliated academic society

  • 1993 - Present, 日本物理学会
  • 1996 - 2020, 日本生物物理学会

Research Themes