Article
Instruments & Instrumentation
Marco Malvestuto, Antonio Caretta, Richa Bhardwaj, Simone Laterza, Fulvio Parmigiani, Alessandro Gessini, Matteo Zamolo, Fabio Galassi, Rudi Sergo, Giuseppe Cautero, Miltcho B. Danailov, Alexander Demidovic, Paolo Sigalotti, Marco Lonza, Roberto Borghes, Adriano Contillo, Alberto Simoncig, Michele Manfredda, Lorenzo Raimondi, Marco Zangrando
Summary: The scope of this paper is to outline the main features and performances of the MagneDyn beamline, designed and built for ultrafast magnetodynamic studies in solids. The high degree of polarization, pulse stability, and photon energy tunability enable advanced time-resolved magnetic dichroic experiments. Two experimental end-stations are available, one with dedicated equipment and the other for user instruments. The combination of these features makes MagneDyn a unique tool for studying ultrafast magnetic and resonant emission phenomena in solids.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Optics
Jiaxun Hou, Thomas Schafer
Summary: In this study, constraints on the temperature dependence of shear viscosity in the superfluid phase of a dilute Fermi gas are established. The analysis is based on experimental measurements of the aspect ratio of a deformed cloud, and it shows that expansion experiments favor a significant decrease in shear viscosity in the superfluid regime.
Article
Astronomy & Astrophysics
Xiongbang Yang, Gang Cao
Summary: The paper investigates the high-energy emission properties of pulsars using numerical simulations and computing magnetospheres, finding that the FIDO model can reproduce the observed characteristics successfully.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Multidisciplinary
Ran Qi, Zheyu Shi, Hui Zhai
Summary: Studied the impact of time-dependent interatomic interactions on quantum gas energy density growth. Results show that controlling the time dependence can affect the rate of energy density growth, which is also significant for experiments with ultracold atomic gases.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Ye Cao, Jing Zhou
Summary: The study of the polaron of an open quantum system is important for verifying the effectiveness of many-body theory and predicting novel quantum phenomena. In this work, the molecular state and spectrum functions of polarons in different dissipation ranges and loss rates are determined through analytical research. The results show how the molecular and polaron states respond to increasing dissipation range.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Mathematics
Emanuela L. Giacomelli
Summary: In this study, we introduce the correlation energy as the difference between the ground state energy and that of the free Fermi gas in a system of interacting fermions. We provide rigorous upper and lower bound estimates for the correlation energy in the dilute regime, with improved accuracy compared to previous results.
JOURNAL OF FUNCTIONAL ANALYSIS
(2023)
Article
Physics, Multidisciplinary
Marco Falconi, Emanuela L. Giacomelli, Christian Hainzl, Marcello Porta
Summary: This study examines the ground state properties of interacting Fermi gases in the dilute regime in three dimensions. The researchers compute the ground state energy of the system for positive interaction potentials and provide improved error estimates on the ground state energy asymptotics in the density. The results offer a new derivation of the formula inspired by Bogoliubov theory.
ANNALES HENRI POINCARE
(2021)
Article
Physics, Mathematical
Amare Abebe, Mudhahir Al Ajmi, Maye Elmardi, Hemwati Nandan, Noor ul Sabah
Summary: This work revisits the shear-free conjecture in general relativity and studies the shear-free condition in the context of Chaplygin-gas cosmology. The study shows that under certain non-trivial conditions, a universe dominated by Chaplygin-gas can allow both expansion and rotation of the fluid simultaneously, unlike the expected results for dust spacetimes.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2021)
Article
Physics, Multidisciplinary
Masaaki Tokieda, Shimpei Endo
Summary: The study reveals that the dissipative quantum dynamics of the Caldirola-Kanai model can be exactly mapped to a dissipationless quantum dynamics under a negative external harmonic potential, even when particles are strongly interacting. The mapping is particularly valid for the unitary Fermi gas, which is relevant for cold atoms and nuclear matters.
FRONTIERS IN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Michael Cromer, Paula A. Vasquez
Summary: Modeling the flow of polymer solutions requires knowledge at different length and time scales. Microscopic models capture polymer behavior accurately but incur high computational cost due to solving a large number of differential equations.
APPLIED SCIENCES-BASEL
(2023)
Article
Physics, Nuclear
C. Wellenhofer, C. Drischler, A. Schwenk
Summary: We discuss high-order calculations in perturbative effective field theory for fermions at low energy scales, focusing on the Fermi-momentum or k(F)a(s) expansion for the ground-state energy of the dilute Fermi gas. Our results show that the expansion is well-converged at fourth order for vertical bar k(F)a(s)vertical bar less than or similar to 0.5, with Pade-Borel resummations improving convergence for vertical bar k(F)a(s)vertical bar less than or similar to 1. These findings provide important constraints for nonperturbative calculations of ultracold atoms and dilute neutron matter.
Article
Physics, Multidisciplinary
Kantaro Honda, Shintaro Taie, Yosuke Takasu, Naoki Nishizawa, Masaya Nakagawa, Yoshiro Takahashi
Summary: We have observed the reversal of magnetic correlation from antiferromagnetic to ferromagnetic in a controlled manner by utilizing on-site twobody losses as a source of dissipation. We measured the dynamics of spin correlation in an isolated double-well optical lattice and observed a ferromagnetic spin correlation, consistent with the Dicke correlation expected in the long-time limit. This work demonstrates the control of quantum magnetism in open quantum systems with dissipation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
B. Abeln, K. Sponselee, M. Diem, N. Pintul, K. Sengstock, C. Becker
Summary: In this study, interisotope interorbital interactions between atoms in Yb-171 and Yb-173 mixture were characterized. The elastic interaction between Yb-173(e)-Yb-171(g) and Yb-173(g)-Yb-171(e) was found to be weakly attractive, with different two-body decay coefficients. By comparing different spin mixtures, the SU(2)⨂SU(6) symmetry of the elastic interactions was experimentally demonstrated. Additionally, the interorbital spin-exchange interaction in Yb-171 was measured and confirmed to be antiferromagnetic.
Article
Astronomy & Astrophysics
Dipika Dash, Samapan Bhadury, Sunil Jaiswal, Amaresh Jaiswal
Summary: In this study, a new framework for deriving relativistic dissipative hydrodynamics from the Boltzmann equation with energy-dependent relaxation time is developed. The framework is shown to be compatible with conservation laws and corrections to transport coefficients due to energy dependence of relaxation time are discussed. The ratios of these transport coefficients are studied using a parametrized relaxation-time, revealing interesting scaling features.
Article
Astronomy & Astrophysics
Dipika Dash, Samapan Bhadury, Sunil Jaiswal, Amaresh Jaiswal
Summary: Development of a new framework for deriving order-by-order hydrodynamics from the Boltzmann equation is necessary to address the violations of conservation laws caused by the widely used Anderson-Witting formalism when relaxation-time depends on particle energy or in a hydrodynamic frame other than the Landau frame. In this study, we generalize an existing framework and extend the Anderson-Witting relaxation-time approximation to derive relativistic dissipative hydrodynamics consistently. The present framework is compatible with conservation laws and yields first-order hydrodynamic equations in the Landau frame. Additionally, corrections to the transport coefficients due to energy dependence of the relaxation-time are observed, indicating deviations from the Anderson-Witting approximation.
Article
Physics, Particles & Fields
Alireza Behtash, Gerald Dunne, Thomas Schafer, Tin Sulejmanpasic, Mithat Unsal
JOURNAL OF HIGH ENERGY PHYSICS
(2018)
Article
Physics, Particles & Fields
Jingyi Chao, Thomas Schafer
Summary: In this study, the role of multiplicative noise in stochastic fluid dynamics was investigated. It was found that multiplicative noise contributes at the same order as non-linear interactions in model B, but is a higher order correction in model H for the relaxation of a scalar density and the tail of the stress tensor correlation function.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Jingyi Chao, Thomas Schafer
Summary: We construct 1PI and 2PI effective actions for stochastic fluid dynamics of a conserved density undergoing diffusive motion. The 1PI action is computed at one-loop order and the 2PI action is approximated at two-loop order. Schwinger-Dyson equations are derived and regularized using Pauli-Villars fields. The resulting equations are numerically solved for a non-critical fluid, revealing the renormalization of the nonlinear coupling due to summation of higher-loop effects. Evidence of a diffuson-cascade, with smaller and smaller exponential suppression for n-loop corrections, is also found.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Nuclear
Chandrodoy Chattopadhyay, Ulrich Heinz, Thomas Schaefer
Summary: We study the hydrodynamic evolution of a quark-gluon gas with nonzero quark masses and net baryon number in its phase diagram. For far-off-equilibrium initial conditions, the expansion trajectories do not follow the simple rules based on the second law of thermodynamics established for ideal or weakly dissipative fluids. We analyze the Bjorken flow in kinetic theory to provide a microscopic understanding of these macroscopic phenomena and ensure their thermodynamic consistency. We identify a phenomenon called viscous cooling, where the temperature decreases faster than in adiabatic expansion due to dissipative effects.
Article
Astronomy & Astrophysics
Thomas Schafer, Vladimir Skokov
Summary: Motivated by the experimental search for the QCD critical point, we performed simulations of a stochastic field theory with relaxational dynamics and verified the dynamic scaling of correlation functions. By studying time dependent correlation functions, we obtained the dynamic critical exponent. We also investigated the relaxation process after a quench and found that it does not follow simple scaling.
Article
Optics
Jiaxun Hou, Thomas Schafer
Summary: In this study, constraints on the temperature dependence of shear viscosity in the superfluid phase of a dilute Fermi gas are established. The analysis is based on experimental measurements of the aspect ratio of a deformed cloud, and it shows that expansion experiments favor a significant decrease in shear viscosity in the superfluid regime.
Article
Astronomy & Astrophysics
A. Behtash, S. Kamata, M. Martinez, T. Schafer, V Skokov
Summary: In this study, we investigate the nonlinear transport processes and hydrodynamization of a gluon system undergoing longitudinal boost-invariant expansion. By examining the behavior of solutions at large and small effective Knudsen numbers, we demonstrate different behaviors and the resummation scheme for each moment. The Yang-Mills plasma exhibits non-Newtonian behavior during hydrodynamizing in the UV regime, while in the IR regime, the constitutive relations can be expressed as a multiparameter transseries.
Article
Physics, Nuclear
Marcus Bluhm, Alexander Kalweit, Marlene Nahrgang, Mesut Arslandok, Peter Braun-Munzinger, Stefan Floerchinger, Eduardo S. Fraga, Marek Gazdzicki, Christoph Hartnack, Christoph Herold, Romain Holzmann, Iurii Karpenko, Masakiyo Kitazawa, Volker Koch, Stefan Leupold, Aleksas Mazeliauskas, Bedangadas Mohanty, Alice Ohlson, Dmytro Oliinychenko, Jan M. Pawlowski, Christopher Plumberg, Gregory W. Ridgway, Thomas Schaefer, Ilya Selyuzhenkov, Johanna Stachel, Mikhail Stephanov, Derek Teaney, Nathan Touroux, Volodymyr Vovchenko, Nicolas Wink
Article
Physics, Nuclear
Paolo Parotto, Marcus Bluhm, Debora Mroczek, Marlene Nahrgang, J. Noronha-Hostler, Krishna Rajagopal, Claudia Ratti, Thomas Schafer, Mikhail Stephanov
Article
Astronomy & Astrophysics
Aleksey Cherman, Syo Kamata, Thomas Schafer, Mithat Unsal
Article
Astronomy & Astrophysics
M. Martinez, T. Schafer, V Skokov
Article
Astronomy & Astrophysics
Marlene Nahrgang, Marcus Bluhm, Thomas Schafer, Steffen A. Bass
Article
Physics, Nuclear
M. Martinez, T. Schafer
Proceedings Paper
Physics, Nuclear
Marcus Bluhm, Marlene Nahrgang, Thomas Schaefer, Steffen A. Bass
17TH INTERNATIONAL CONFERENCE ON STRANGENESS IN QUARK MATTER (SQM 2017)
(2018)
Article
Optics
Mauricio Martinez, Thomas Schafer
