Browsing PubMed İndeksli Yayınlar Koleksiyonu by Author "Berker, A. Nihat"
Now showing items 1-16 of 16
-
Across dimensions: Two- and three-dimensional phase transitions from the iterative renormalization-group theory of chains
Keçoğlu, İbrahim; Berker, A. Nihat (2020)Sharp two- and three-dimensional phase transitional magnetization curves are obtained by an iterative renormalization-group coupling of Ising chains, which are solved exactly. The chains by themselves do not have a phase ... -
Asymmetric phase diagrams, algebraically ordered Berezinskii-Kosterlitz-Thouless phase, and peninsular Potts flow structure in long-range spin glasses
Gurleyen, S. Efe; Berker, A. Nihat (Amer Physical Soc, 2022)The Ising spin-glass model on the three-dimensional (d = 3) hierarchical lattice with long-range ferromagnetic or spin-glass interactions is studied by the exact renormalization-group solution of the hierarchical lattice. ... -
Complete density calculations of q-state Potts and clock models: Reentrance of interface densities under symmetry breaking
Artun, E. Can; Berker, A. Nihat (Amer Physical Soc, 2020)All local bond-state densities are calculated for q-state Potts and clock models in three spatial dimensions, d = 3. The calculations are done by an exact renormalization group on a hierarchical lattice, including the ... -
COVID-19 modeling based on real geographic and population data
Baysazan, Emir; Berker, A. Nihat; Mandal, Hasan; Kaygusuz, Hakan (Tubitak Scientific & Technological Research Council Turkey, 2023)Background/aim: Intercity travel is one of the most important parameters for combating a pandemic. The ongoing COVID-19 pandemic has resulted in different computational studies involving intercity connections. In this ... -
Devil's staircase continuum in the chiral clock spin glass with competing ferromagnetic-antiferromagnetic and left-right chiral interactions
Caglar, Tolga; Berker, A. Nihat (Amer Physical Soc., 2017)The chiral clock spin-glass model with q = 5 states with both competing ferromagnetic-antiferromagnetic and left-right chiral frustrations is studied in d = 3 spatial dimensions by renormalization-group theory. The global ... -
The effect of weekend curfews on epidemics: a Monte Carlo simulation
Kaygusuz, Hakan; Berker, A. Nihat (Tubitak Scientific & Technical Research Council Turkey, 2021)The ongoing COVID-19 pandemic is being responded with various methods, applying vaccines, experimental treatment options, total lockdowns or partial curfews. Weekend curfews are among the methods for reducing the number ... -
First-order to second-order phase transition changeover and latent heats of q-state Potts models in d=2,3 from a simple Migdal-Kadanoff adaptation
Devre, H. Yagiz; Berker, A. Nihat (Amer Physical Soc, 2022)The changeover from first-order to second-order phase transitions in q-state Potts models is obtained at q(c) = 2 in spatial dimension d = 3 and essentially at q(c) = 4 in d = 2, using a physically intuited simple adaptation ... -
Frustrated Potts model: Multiplicity eliminates chaos via reentrance
Türkoğlu, Alpar; Berker, A. Nihat (Amer Physical Soc, 2020)The frustrated q-state Potts model is solved exactly on a hierarchical lattice, yielding chaos under rescaling, namely, the signature of a spin-glass phase, as previously seen for the Ising (q = 2) model. However, the ... -
Lower critical dimension of the random-field XY model and the zero-temperature critical line
Akin, Kutay; Berker, A. Nihat (Amer Physical Soc, 2022)The random-field XY model is studied in spatial dimensions d = 3 and 4, and in between, as the limit q -> infinity of the q-state clock models, by the exact renormalization-group solution of the hierarchical lattice or, ... -
Maximally random discrete-spin systems with symmetric and asymmetric interactions and maximally degenerate ordering
Atalay, Bora; Berker, A. Nihat (Amer Physical Soc., 2018)Discrete-spin systems with maximally random nearest-neighbor interactions that can be symmetric or asymmetric ferromagnetic or antiferromagnetic including off-diagonal disorder are studied for the number of states q = 34 ... -
Merged Potts-clock model: Algebraic and conventional multistructured multicritical orderings in two and three dimensions
Artun, E. Can; Berker, A. Nihat (Amer Physical Soc, 2023)A spin system is studied with simultaneous permutation-symmetric Potts and spin-rotation-symmetric clock interactions in spatial dimensions d = 2 and 3. The global phase diagram is calculated from the renormalization-group ... -
Metastable Potts droplets
Artun, E. Can; Berker, A. Nihat (AMER PHYSICAL SOC, 2021-03)The existence and limits of metastable droplets have been calculated using finite-system renormalization-group theory, for q-state Potts models in spatial dimension d = 3. The dependence of the droplet critical sizes on ... -
Metastable reverse-phase droplets within ordered phases: Renormalization-group calculation of field and temperature dependence of limiting size
Eren, Ege; Berker, A. Nihat (AMER PHYSICAL SOC, 2020)Metastable reverse-phase droplets are calculated by renormalization-group theory by evaluating the magnetization of a droplet under magnetic field, matching the boundary condition with the reverse phase and noting whether ... -
Nematic ordering in the Heisenberg spin-glass system in three dimensions
Tunca, Egemen; Berker, A. Nihat (Amer Physical Soc, 2023)Nematic ordering, where the spins globally align along a spontaneously chosen axis irrespective of direction, occurs in spin-glass systems of classical Heisenberg spins in d = 3. In this system where the nearest-neighbor ... -
Phase transitions between different spin-glass phases and between different chaoses in quenched random chiral systems
Çağlar, Tolga; Berker, A. Nihat (Amer Physical Soc., 2017)The left-right chiral and ferromagnetic-antiferromagnetic double-spin-glass clock model with the crucially even number of states q = 4 and in three dimensions d = 3 has been studied by renormalization-group theory. We find ... -
Spin-s spin-glass phases in the d=3 Ising model
Artun, E. Can; Berker, A. Nihat (Amer Physical Soc, 2021)All higher-spin (s >= 1/2) Ising spin glasses are studied by renormalization-group theory in spatial dimension d = 3, exactly on a d = 3 hierarchical model and, simultaneously, by the Migdal-Kadanoff approximation on the ...