Article
Physics, Multidisciplinary
Ahana Chakraborty, Rajdeep Sensarma
Summary: This study introduces a new field theoretic method for calculating Renyi entropy of interacting bosons in subsystems without using replica methods. The method can be applied to dynamics of open and closed quantum systems, and can determine the relationship between the initial state and final density matrix to predict the behavior of entropy over time. The approach also shows that the entropy in non-Markovian dynamics approaches a steady-state value with exponents determined by nonanalyticities of the system's environment.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Ruben Pena, Thi Ha Kyaw, Guillermo Romero
Summary: This study demonstrates the stability of fractional resonance under local noise models and its potential implementation in existing noisy intermediate-scale quantum devices. The findings suggest a possible pathway towards a stable nonequilibrium state of matter, with potential applications in quantum information processing using quantum memories.
Article
Materials Science, Multidisciplinary
Adrian B. Culver, Natan Andrei
Summary: This study presents a method for calculating the time-dependent many-body wavefunction in the non-equilibrium Kondo model, showing applicability beyond using the Bethe ansatz and unveiling a universal regime in the case of strong ferromagnetic coupling. The results reveal a current-carrying non-equilibrium steady state that converges to all orders in the steady-state limit, providing insights into the behavior of the Kondo model in different coupling regimes.
Article
Chemistry, Physical
Alexander Stadik, Gerhard Kahl
Summary: By using Monte Carlo simulations, the properties of deformable fluid particles in a porous matrix were studied, showing that the change in shape is related to changes in energy and has a distinct impact on the system's static and dynamic properties.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
T. Hvozd, Yu Kalyuzhnyi, V. Vlachy, P. T. Cummings
Summary: Research shows that irregular colloids with three and four equivalent patches, confined in a random porous medium, undergo re-entrant gas-liquid phase separation at low temperatures, with liquid phase density approaching zero. This phenomenon provides new insights into the phase behavior of biological macromolecules in crowded environments.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
M. Muhsin, F. Adersh, M. Sahoo
Summary: The dynamics of a charged inertial active Ornstein-Uhlenbeck particle in viscoelastic suspension is studied. The steady state response of a confined harmonic particle to a magnetic field is found to exhibit interesting features due to the interplay of elastic dissipation and active fluctuations. The steady state MSD is enhanced or suppressed with increasing magnetic field strength depending on the relative time scales of activity, elastic dissipation, and memory in the medium.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
J. Baetge, Y. Ke, C. Kaspar, M. Thoss
Summary: The hierarchical equations of motion approach allows for numerically exact simulation of nonequilibrium transport in general open quantum systems involving multiple macroscopic environments. The method's performance has been demonstrated in a nanosystem model, showing intricate interplay between electronic and vibrational degrees of freedom in transport processes. Discussions on the use of importance criteria to improve efficiency have also been included.
Article
Mechanics
E. Gravanis, E. Akylas, G. Livadiotis
Summary: The diffusion of particles with kappa distributed velocities is strongly affected by statistical correlations. The study shows that the superstatistics interpretation is fundamental for understanding kappa distribution, while focusing on a single degree of freedom is inconsistent with this interpretation. The authors also find that the mean energy per degree of freedom is the superstatistical fluctuating temperature in a system with a large number of particles, highlighting the importance of considering correlated degrees of freedom.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Chemistry, Physical
Yaxin Xu, Sho C. Takatori
Summary: Understanding nonequilibrium interactions in multi-component colloidal suspensions is crucial for various dynamic processes including self-assembly and material processing. This study develops a first-principle framework using the Smoluchowski equation and Brownian dynamics simulations to investigate a bidisperse colloidal suspension with depletants. The results of nonlinear microrheology demonstrate that effective depletion interactions between driven colloids are influenced by equilibrium and cannot be predicted by equilibrium-based pair potentials. The interplay between Brownian relaxation timescales of different species is shown to play a critical role in determining the viscosity of multi-component suspensions.
Article
Chemistry, Multidisciplinary
David Abella, Giancarlo Franzese, Javier Hernandez-Rojas
Summary: Many-body interactions in water are important and difficult to treat in atomistic models. Polarizable models explicitly include these interactions but are computationally expensive. We evaluated the relevance of different coordination shells in these interactions and found that including the first coordination shell approximates the global energy minimum within 5%. This result holds for three different polarizable models, suggesting a strategy for developing reliable and computationally efficient many-body potentials for water.
Article
Physics, Fluids & Plasmas
Domingos S. P. Salazar
Summary: The detailed fluctuation theorem (DFT) provides a statement about the asymmetry in the statistics of entropy production. It has been found that the DFT imposes a negative tight lower bound for the skewness of entropy production as a function of the mean.
Article
Multidisciplinary Sciences
D. Bluvstein, A. Omran, H. Levine, A. Keesling, G. Semeghini, S. Ebadi, T. T. Wang, A. A. Michailidis, N. Maskara, W. W. Ho, S. Choi, M. Serbyn, M. Greiner, V. Vuletic, M. D. Lukin
Summary: The study demonstrates that coherent revivals associated with quantum many-body scars can be stabilized by periodic driving, generating a robust subharmonic response akin to discrete timecrystalline order. This finding provides new ways to control complex dynamics in many-body systems and may have potential applications in quantum information science.
Article
Mathematics
Dwueng-Chwuan Jhwueng
Summary: Gaussian processes, specifically the Brownian bridge and Ornstein-Uhlenbeck bridge, are proposed to model continuous trait evolution of related species along phylogenetic trees. Traitgrams are generated to display the evolutionary trajectories. These novel models are applied to study body mass evolution of a group of marsupial species.
Article
Physics, Multidisciplinary
Corneel Casert, Tom Vieijra, Stephen Whitelam, Isaac Tamblyn
Summary: Researchers utilized a neural-network ansatz originally designed for quantum systems to study dynamical large deviations in classical systems, exploring the deviations in model glasses and kinetically constrained models in two dimensions. This study presents the first finite size-scaling analysis of the large-deviation functions of the two-dimensional Fredrickson-Andersen model and investigates the spatial structure of high-activity sectors in the South-or-East model, showcasing the wide applicability of the neural-network state ansatz in physics.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Takahiro Orito, Yoshihito Kuno, Ikuo Ichinose
Summary: The study reveals that a flat-band fermion system with interactions but without disorders exhibits nonthermalized ergodicity-breaking dynamics, similar to many-body localization (MBL). The dynamics of two particles show that the modification of states is influenced by the strength of interactions, leading to instability of local integrals of motion (LIOMs). Numerical investigation of many-body dynamics at finite fillings using the time-evolving block decimation (TEBD) method demonstrates nonthermal and low entangled dynamics, a characteristic of disorder-free flat-band many-body localization (FMBL).
Review
Physics, Condensed Matter
Sophie Hermann, Matthias Schmidt
Summary: Noether's theorem plays a fundamental role in linking conservation laws to symmetries in physical systems. Recent research has shown that this reasoning also applies to thermal systems. In this study, we provide a pedagogical introduction to the application of Noether's reasoning to ideal sedimentation in the canonical ensemble. By treating mathematical objects like the free energy as functionals, we were able to derive identities that express properties of macroscopic average forces and molecularly resolved correlations in many-body systems.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Multidisciplinary
Johannes Renner, Matthias Schmidt, Daniel de las Heras
Summary: The velocity field in a moving fluid is affected by its inherent viscous behavior, which helps to dampen any inhomogeneities. Both bulk and shear effects, related to the divergence and curl of the velocity field, play a role in this process. Memory also plays a significant role on molecular time scales beyond the Navier-Stokes description. Through molecular and overdamped Brownian dynamics many-body simulations, it has been demonstrated that similar viscous effects also act on the acceleration field, which can be quantitatively described using simple exponentially decaying memory kernels. The simultaneous use of velocity and acceleration fields allows for the description of fast dynamics on molecular scales.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Iman Abdoli, Rene Wittmann, Joseph Michael Brader, Jens-Uwe Sommer, Hartmut Loewen, Abhinav Sharma
Summary: We propose a mesoscopic Brownian magneto heat pump that can function as both a heat engine and a refrigerator. By controlling the motion of a single charged Brownian particle with an external magnetic field, the maximum power output of the engine and the performance of the refrigerator can be optimized by tuning the applied magnetic field. The key properties of the engine, such as the direction of motion and the torque exerted on the particle, can also be adjusted by varying the strength and direction of the magnetic field.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
S. M. Tschopp, J. M. Brader
Summary: Researchers have developed a superadiabatic dynamical density functional theory for describing inhomogeneous fluids out-of-equilibrium. By incorporating the dynamics of the inhomogeneous two-body correlation functions, they obtained superadiabatic forces directly from the microscopic interparticle interactions. The theory showed improved accuracy and agreement with simulation data compared to standard approaches.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Florian Sammueller, Daniel de las Heras, Matthias Schmidt
Summary: In this study, the stationary flow of a colloidal gel under an inhomogeneous external shear force is investigated using adaptive Brownian dynamics simulations. The results show remarkable modulations in the one-body density profile of the gel under the shear force, indicating a strong non-equilibrium response characteristic of the gel state. The flow and structure of the stationary state are driven by significant viscous and structural superadiabatic forces.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
S. M. Tschopp, H. D. Vuijk, J. M. Brader
Summary: Superadiabatic dynamical density functional theory (superadiabatic-DDFT) is used to investigate the response of interacting Brownian particles to time-dependent external driving. The theory accurately predicts the time-evolution of the one-body density without the need for adjustable parameters or simulation input. Comparison with other methods shows that superadiabatic-DDFT gives reliable results.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Editorial Material
Physics, Condensed Matter
Daniel de las Heras, Toni Zimmermann, Florian Sammueller, Sophie Hermann, Matthias Schmidt
Summary: We argue for the development of a comprehensive dynamical theory to understand and predict nonequilibrium phenomena in soft matter. We discuss the limitations of dynamical density functional theory (DDFT) and propose the need for a systematic understanding of the dynamical functional relationships governing true nonequilibrium physics. We demonstrate the potential of power functional theory by machine learning the kinematic map of a steady sedimentation flow and designing the steady state dynamics for various density modulations. This overcomes the conceptual constraints of DDFT and its limited analytical approximations.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Condensed Matter
Johannes Renner, Matthias Schmidt, Daniel de las Heras
Summary: We propose a method to sample the orientational distribution function in computer simulations based on torque balance equation for anisotropic particles. The method reconstructs the distribution function by integrating the torque acting on the particles rather than using traditional event counting. The torque sampling method shows improved accuracy in two- and three-dimensions compared to the traditional counting method, and it is independent of the bin size, allowing for arbitrarily small angular resolutions.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Condensed Matter
Tobias Eckert, Nico C. X. Stuhlmueller, Florian Sammueller, Matthias Schmidt
Summary: In this article, we demonstrate how three one-body fluctuation profiles can be obtained from statistical mechanical description of classical particle systems. We also provide various equivalent routes to define these fluctuation profiles, making it easier to calculate them numerically in inhomogeneous equilibrium systems. We further derive properties such as hard wall contact theorems and new types of inhomogeneous one-body Ornstein-Zernike equations based on this framework. The accessibility of these fluctuation profiles is exemplified through grand canonical Monte Carlo simulations of confined hard sphere, Gaussian core, and Lennard-Jones fluids.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Florian Sammueller, Sophie Hermann, Daniel de las Heras, Matthias Schmidt
Summary: Liquid structure possesses inherent thermal invariance against spatial transformation and is characterized by two-body correlation functions. Simulations of different systems illustrate the fundamental role of these correlators in describing the spatial structure.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Florian Sammueller, Sophie Hermann, Matthias Schmidt
Summary: This study reexamines the results obtained with force-DFT, a recently proposed density functional theory framework based on forces. By comparing the density profiles of homogeneous and inhomogeneous hard sphere fluids to those obtained from standard DFT and computer simulations, it is found that the equilibrium force-DFT does not improve upon the standard Rosenfeld functional, as demonstrated by the comparison to grand canonical Monte Carlo simulations. The same behavior is observed in the relaxation dynamics, where a hybrid scheme combining standard and force-DFT results is shown to rectify these deficiencies both in equilibrium and dynamical cases.
Article
Chemistry, Physical
Tobias Eckert, Matthias Schmidt, Daniel de las Heras
Summary: We theoretically study the effect of a gravitational field on the equilibrium behavior of a colloidal suspension of rods with different aspect ratios. The system's bulk phases are described by analytical equations of state. The presence of the gravitational field significantly enriches the bulk phenomenology. In a suspension of elongated rods with five stable phases in bulk, the gravitational field stabilizes up to fifteen different stacking sequences. The sample height has a non-trivial effect on the stable stacking sequence.
Article
Physics, Fluids & Plasmas
Salomee M. Tschopp, Florian Sammueller, Sophie Hermann, Matthias Schmidt, Joseph M. Brader
Summary: When a fluid is subjected to an external field, the density becomes spatially inhomogeneous, and the two-body correlations provide a statistical description of the microstructure of the fluid and the average interparticle force. This study presents a theoretical framework based on two-body correlation functions for the description of inhomogeneous many-body systems. By considering local Noether-invariance, the Yvon-Born-Green equation is established as a local force-balance within the fluid. The force-based theory offers an alternative to standard density functional theory for the study of inhomogeneous systems in and out of equilibrium.
Article
Physics, Multidisciplinary
Tobias Eckert, Matthias Schmidt, Daniel de las Heras
Summary: In this study, we investigate the effect of gravity on a plate-sphere colloidal mixture using a theoretical model. The results show that there is a complex interplay between gravity, sample height, and bulk phase separation, leading to the appearance of various stacking sequences. By studying the thicknesses of the layers in the stacking sequences, microscopic information of the mixture can be obtained, and the relationship between colloidal concentrations and buoyant masses can be inferred. Additionally, new phenomena that can be experimentally tested are predicted, such as the nontrivial evolution of the stacking sequence with increasing sample height where new layers appear either at the top or at the bottom of the sample.
PHYSICAL REVIEW RESEARCH
(2022)
