Publications

Order by: publication date number of citations

• Prethermalization in coupled one-dimensional quantum gases

  Maciej Łebek, Miłosz Panfil, Robert M. Konik

  SciPost Phys. 17, 007 (2024) · published 10 July 2024 | Toggle abstract · pdf

  We consider the problem of the development of steady states in one-dimensional Bose gas tubes that are weakly coupled to one another through a density-density interaction. We analyze this development through a Boltzmann collision integral approach. We argue that when the leading order of the collision integral, where single particle-hole excitations are created in individual gases, is dominant, the state of the gas evolves first to a non-thermal fixed point, i.e. a prethermalization plateau. This order is dominant when a pair of tubes are inequivalent with, say, different temperatures or different effective interaction parameters, $\gamma$. When both tubes are in the strongly interacting regime we additionally characterize this non-thermal prethermalization plateau by constructing the quasi-conserved quantities that control the existence of this plateau as well as the associated generalized Gibbs ensemble.

  2 citations

• Constructing non-Abelian quantum spin liquids using combinatorial gauge symmetry

  Dmitry Green, Claudio Chamon

  SciPost Phys. 15, 067 (2023) · published 22 August 2023 | Toggle abstract · pdf

  We construct Hamiltonians with only 1- and 2-body interactions that exhibit an exact non-Abelian gauge symmetry (specifically, combinatiorial gauge symmetry). Our spin Hamiltonian realizes the quantum double associated to the group of quaternions. It contains only ferromagnetic and anti-ferromagnetic $ZZ$ interactions, plus longitudinal and transverse fields, and therefore is an explicit example of a spin Hamiltonian with no sign problem that realizes a non-Abelian topological phase. In addition to the spin model, we propose a superconducting quantum circuit version with the same symmetry.

  2 citations

• An investigation of the appearance of a long range nuclear potential in ultra low energy nuclear synthesis

  Shinsho Oryu, Takashi Watanabe, Yasuhisa Hiratsuka, Masayuki Takeda

  SciPost Phys. Proc. 3, 050 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new potential, the $general$ $particle$ $transfer$ $potential$: so called ``GPT'' potential was represented in the previous paper which indicates a Yukawa-type potential for shorter range, but a $1/r^n$-type potential for longer range where $n=2$ includes the Efimov-like potential in the hadron system. In order to confirm the existence of a GPT potential, we investigate the possibility of Cs+2d$\rightarrow$La reaction on the three-ion quasi-molecule CsD$_2$ which is covered by twelve Pd or a CsD$_2$Pd$_{12}$-cluster, where the three-body bound states and wave functions for D-Cs-D molecular and d-Cs-d nuclear systems are calculated. We obtain an approximate E2-transition from the molecular states to the nuclear states. The transition ratio between the short range nuclear potential with the $1/r^2$-type long range potential and without long range potential is $W_{i\rightarrow f}^{E2';L}/W_{i\rightarrow f}^{E2';S}\approx 10^8$. If the reaction Cs+2D$\rightarrow$La is experimentally observed, then the existence of the GPT potential could be confirmed.

  2 citations

• CORSIKA 8 - the next-generation air shower simulation framework

  Tim Huege for the CORSIKA 8 Collaboration

  SciPost Phys. Proc. 13, 028 (2023) · published 29 September 2023 | Toggle abstract · pdf

  For more than 20 years, the community has heavily relied on CORSIKA for the simulation of extensive air showers, their Cherenkov light emission and their radio signals. While tremendously successful, the Fortran-based monolithic design of CORSIKA up to version 7 limits adaptation to new experimental needs, for example, in complex scenarios where showers transition from air into dense media, and to new computing paradigms such as the use of multi-core and GPU parallelization. With CORSIKA 8, we have reimplemented the core functionality of CORSIKA in a modern, modular, C++-based simulation framework, and successfully validated it against CORSIKA 7. Here, we discuss the philosophy of CORSIKA 8, showcase some example applications, and present the current state of implementation as well as the plans for the future.

  2 citations

• Transport and magnetic properties in the Nd diluted system Y$_{1-x}$Nd$_{x}$Co$_{2}$Zn$_{20}$

  Rikako Yamamoto, Yasuyuki Shimura, Kazunori Umeo, Toshiro Takabatake, Takahiro Onimaru

  SciPost Phys. Proc. 11, 010 (2023) · published 5 June 2023 | Toggle abstract · pdf

  We report the electrical resistivity, specific heat, and magnetization measurements of Y$_{1-x}$Nd$_{x}$Co$_{2}$Zn$_{20}$ for $0.017 \leq x \leq 0.95$. The Schottky-type specific heat peak at around 13 K for all the samples is reproduced by the crystalline electric field model with the $\Gamma_{6}$ doublet ground state of a Nd$^{3+}$ ion. The magnetization and magnetic susceptibility data of the samples for $x \leq 0.06$ are well reproduced by the calculation without intersite magnetic interactions among Nd moments. Therefore, the dilute Nd system Y$_{1-x}$Nd$_{x}$Co$_{2}$Zn$_{20}$ for $x \leq 0.06$ is a good candidate to study on-site interaction of the $\Gamma_{6}$ doublet ground state of 4$f$ electrons with conduction electrons.

  2 citations

• Classical boundary field theory of Jacobi sigma models by Poissonization

  Ion V. Vancea

  SciPost Phys. Proc. 4, 011 (2021) · published 13 August 2021 | Toggle abstract · pdf

  In this paper, we are going to construct the classical field theory on the boundary of the embedding of $\mathbb{R} \times S^{1}$ into the manifold $M$ by the Jacobi sigma model. By applying the poissonization procedure and by generalizing the known method for Poisson sigma models, we express the fields of the model as perturbative expansions in terms of the reduced phase space of the boundary. We calculate these fields up to the second order and illustrate the procedure for contact manifolds.

  2 citations

• R-matrices and Miura operators in 5d Chern-Simons theory

  Nafiz Ishtiaque, Saebyeok Jeong, Yehao Zhou

  SciPost Phys. Core 8, 003 (2025) · published 13 January 2025 | Toggle abstract · pdf

  We derive Miura operators for $W$- and $Y$-algebras from first principles as the expectation value of the intersection between a topological line defect and a holomorphic surface defect in 5-dimensional non-commutative $\mathfrak{gl}(1)$ Chern-Simons theory. The expectation value, viewed as the transition amplitude for states in the defect theories forming representations of the affine Yangian of $\mathfrak{gl}(1)$, satisfies the Yang-Baxter equation and is thus interpreted as an R-matrix. To achieve this, we identify the representations associated with the line and surface defects by calculating the operator product expansions (OPEs) of local operators on the defects, as conditions that anomalous Feynman diagrams cancel each other. We then evaluate the expectation value of the defect intersection using Feynman diagrams. When the line and surface defects are specified, we demonstrate that the expectation value precisely matches the Miura operators and their products.

  2 citations

• Two-point superstring tree amplitudes using the pure spinor formalism

  Sitender Pratap Kashyap

  SciPost Phys. Core 8, 005 (2025) · published 14 January 2025 | Toggle abstract · pdf

  We provide a prescription for computing two-point tree-level amplitudes in the pure spinor formalism that provides finite results that agree with the corresponding expression in the field theories. In [J. High Energy Phys. 07, 139 (2019), Phys. Lett. B 800, 135078 (2020)], the same result was discovered in the bosonic strings with indications of generalization to superstrings in the Ramond-Neveu-Schwarz formalism. Pure spinor formalism is the unique super-Poincare covariant approach to quantizing superstrings [J. High Energy Phys. 04, 018 (2000)]. Since the pure spinor formalism is equivalent to other superstring formalisms, it verifies the above claim. We introduce a mostly BRST exact operator to achieve this.

  2 citations

• Variation along liquid isomorphs of the driving force for crystallization

  Ulf R. Pedersen, Karolina Adrjanowicz, Kristine Niss, Nicholas P. Bailey

  SciPost Phys. 2, 022 (2017) · published 21 June 2017 | Toggle abstract · pdf

  We investigate the variation of the driving force for crystallization of a supercooled liquid along isomorphs, curves along which structure and dynamics are invariant. The variation is weak, and can be predicted accurately for the Lennard-Jones fluid using a recently developed formalism and data at a reference temperature. More general analysis allows interpretation of experimental data for molecular liquids such as dimethyl phthalate and indomethacin, and suggests that the isomorph scaling exponent $\gamma$ in these cases is an increasing function of density, although this cannot be seen in measurements of viscosity or relaxation time.

  2 citations

• Topological interpretation of color exchange invariants: hexagonal lattice on a torus

  Olivier Cépas, Peter M. Akhmetiev

  SciPost Phys. 10, 042 (2021) · published 18 February 2021 | Toggle abstract · pdf

  We explain a correspondence between some invariants in the dynamics of color exchange in a 2d coloring problem, which are polynomials of winding numbers, and linking numbers in 3d. One invariant is visualized as linking of lines on a special surface with Arf-Kervaire invariant one, and is interpreted as resulting from an obstruction to transform the surface into its chiral image with special continuous deformations. We also consider additional constraints on the dynamics and see how the surface is modified.

  2 citations