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Ramsey spectroscopy has become a powerful technique for probing non-equilibrium dynamics of internal (pseudospin) degrees of freedom of interacting systems. In many theoretical treatments, the key to understanding the dynamics has been to…

Atomic Physics · Physics 2015-06-18 A. P. Koller , M. Beverland , A. V. Gorshkov , A. M. Rey

We analyze the transition into the most favorable ordered state for a system of 2D fermions with spin and valley degrees of freedom. We show that for a range of rotationally invariant dispersions, the ordering transition is highly…

Strongly Correlated Electrons · Physics 2024-06-10 Zachary M. Raines , Leonid I. Glazman , Andrey V. Chubukov

Systems with quenched disorder possess complex energy landscapes that are challenging to explore under the conventional Monte Carlo method. In this work, we implement an efficient entropy sampling scheme for accurate computation of the…

Disordered Systems and Neural Networks · Physics 2025-05-08 Yi Liu , Ding Wang , Xin Wang , Dao-Xin Yao , Lei-Han Tang

We present the full analysis of the normal state of the spin-fermion model near the antiferromagnetic instability in two dimensions. This model describes low-energy fermions interacting with their own collective spin fluctuations, which…

Superconductivity · Physics 2007-05-23 Ar. Abanov , Andrey V. Chubukov , J. Schmalian

The Ising antiferromagnet is an important statistical physics model with close connections to the {\sc Max Cut} problem. Combining spatial mixing arguments with the method of moments and the interpolation method, we pinpoint the replica…

Combinatorics · Mathematics 2020-11-13 Amin Coja-Oghlan , Philipp Loick , Balázs F. Mezei , Gregory B. Sorkin

We study the 2-dimensional Ising model at critical temperature on a simply connected subset $\Omega_{\delta}$ of the square grid $\delta\mathbb{Z}^{2}$. The scaling limit of the critical Ising model is conjectured to be described by…

Mathematical Physics · Physics 2018-11-26 Reza Gheissari , Clément Hongler , S. C. Park

This paper considers synchronous discrete-time dynamical systems on graphs based on the threshold model. It is well known that after a finite number of rounds these systems either reach a fixed point or enter a 2-cycle. The problem of…

Discrete Mathematics · Computer Science 2022-02-04 Volker Turau

We study zeros of the partition functions of ferromagnetic 2-state spin systems in terms of the external field, and obtain new zero-free regions of these systems via a refinement of Asano's and Ruelle's contraction method. The strength of…

Data Structures and Algorithms · Computer Science 2019-07-16 Heng Guo , Jingcheng Liu , Pinyan Lu

We study the computational complexity of approximately computing the partition function of a spin system. Techniques based on standard counting-to-sampling reductions yield $\tilde{O}(n^2)$-time algorithms, where $n$ is the size of the…

Data Structures and Algorithms · Computer Science 2026-04-03 Xiaoyu Chen , Zongchen Chen , Kuikui Liu , Xinyuan Zhang

An emerging trend in approximate counting is to show that certain `low-temperature' problems are easy on typical instances, despite worst-case hardness results. For the class of regular graphs one usually shows that expansion can be…

Data Structures and Algorithms · Computer Science 2024-02-06 Charles Carlson , Ewan Davies , Alexandra Kolla

We study the identity testing problem in the context of spin systems or undirected graphical models, where it takes the following form: given the parameter specification of the model $M$ and a sampling oracle for the distribution…

Data Structures and Algorithms · Computer Science 2019-06-21 Ivona Bezakova , Antonio Blanca , Zongchen Chen , Daniel Štefankovič , Eric Vigoda

We consider ferromagnetic Ising models on graphs that converge locally to trees. Examples include random regular graphs with bounded degree and uniformly random graphs with bounded average degree. We prove that the "cavity" prediction for…

Probability · Mathematics 2016-09-08 Amir Dembo , Andrea Montanari

Altermagnets, characterized by zero net magnetization and momentum-dependent spin splitting, have recently garnered significant attention due to their potential applications in a variety of fields. Here, we propose a symmetry-engineering…

Mesoscale and Nanoscale Physics · Physics 2025-07-15 Dong Liu , Sike Zeng , Ji-Hai Liao , Yu-Jun Zhao

The exact 2-spinon part of the dynamic spin structure factor $S_{xx}(Q,\omega)$ for the one-dimensional $s$=1/2 $XXZ$ model at $T$=0 in the antiferromagnetically ordered phase is calculated using recent advances by Jimbo and Miwa in the…

Condensed Matter · Physics 2009-10-30 A. Hamid Bougourzi , Michael Karbach , Gerhard Müller

We present a numerical analysis of the entropy rate and statistical complexity related to the spin flip dynamics of the 2D Ising Ferromagnet at different temperatures T. We follow an information theoretic approach and test three different…

Statistical Mechanics · Physics 2012-07-02 O. Melchert , A. K. Hartmann

Spin systems have emerged as powerful tools for understanding collective phenomena in complex systems. In this work, we investigate the Ashkin--Teller (AT) model on random scale-free networks using mean-field theory, which extends the…

Physics and Society · Physics 2025-10-29 Cook Hyun Kim , Hoyun Choi , Joonsung Jung , B. Kahng

The emergence of massive graph data sets requires fast mining algorithms. Centrality measures to identify important vertices belong to the most popular analysis methods in graph mining. A measure that is gaining attention is forest…

Data Structures and Algorithms · Computer Science 2021-01-18 Alexander van der Grinten , Eugenio Angriman , Maria Predari , Henning Meyerhenke

We suggest a generalization of the Feynman path integral to an integral over random surfaces. The proposed action is proportional to the linear size of the random surfaces and is called gonihedric. The convergence and the properties of the…

High Energy Physics - Theory · Physics 2016-12-13 George Savvidy

We use Monte Carlo and Transfer Matrix methods in combination with extrapolation schemes to determine the phase diagram of the 2D super-antiferromagnetic (SAF) Ising model with next-nearest-neighbor (nnn) interactions in a magnetic field.…

Statistical Mechanics · Physics 2015-06-15 A. saguia , B. Boechat , O. F. de Alcantara Bonfim , J. Florencio

A powerful existing technique for evaluating statistical mechanical quantities in two-dimensional Ising models is based on constructing a matrix representing the nearest neighbor spin couplings and then evaluating the Pfaffian of the…

Disordered Systems and Neural Networks · Physics 2013-04-16 Creighton K. Thomas , A. Alan Middleton