Detecting chimeras by eigenvalue decomposition of the bivariate local order parameter

2020 ◽  
Vol 130 (2) ◽  
pp. 28003
Author(s):  
Fatemeh Parastesh ◽  
Hamed Azarnoush ◽  
Sajad Jafari ◽  
Matjaž Perc
2003 ◽  
Vol 17 (10n12) ◽  
pp. 487-490
Author(s):  
S. I. Belov ◽  
B. I. Kochelaev

In this report we present our study of two-dimensional Heisenberg magnets based on the picture of thermally excited skyrmions. The local order parameter, energy spectrum of elementary spin excitations above the skyrmion background, the skyrmion averaged radius and static magnetic susceptibility were obtained by the Green functions method. There was calculated the rate of nuclear relaxation caused by the interaction of nuclear spins with above mentioned spin excitations. The contribution of Moriya–Dsyloshinskii and anisotropic symmetric interactions into EPR line was considered. A comparison with NMR and neutron scattering experiments in cuprates and with the results obtained by other methods is given. We discuss the consequences of an interaction between skyrmions as the result of the spin fluctuations.


1996 ◽  
Vol 76 (25) ◽  
pp. 4769-4772 ◽  
Author(s):  
D. Mao ◽  
P. C. Taylor ◽  
Sarah R. Kurtz ◽  
M. C. Wu ◽  
W. A. Harrison

2018 ◽  
Vol 175 ◽  
pp. 03008 ◽  
Author(s):  
Maksim Ulybyshev ◽  
Christopher Winterowd ◽  
Savvas Zafeiropoulos

The detection of the (semi)metal-insulator phase transition can be extremely difficult if the local order parameter which characterizes the ordered phase is unknown. In some cases, it is even impossible to define a local order parameter: the most prominent example of such system is the spin liquid state. This state was proposed to exist in the Hubbard model on the hexagonal lattice in a region between the semimetal phase and the antiferromagnetic insulator phase. The existence of this phase has been the subject of a long debate. In order to detect these exotic phases we must use alternative methods to those used for more familiar examples of spontaneous symmetry breaking. We have modified the Backus-Gilbert method of analytic continuation which was previously used in the calculation of the pion quasiparticle mass in lattice QCD. The modification of the method consists of the introduction of the Tikhonov regularization scheme which was used to treat the ill-conditioned kernel. This modified Backus-Gilbert method is applied to the Euclidean propagators in momentum space calculated using the hybrid Monte Carlo algorithm. In this way, it is possible to reconstruct the full dispersion relation and to estimate the mass gap, which is a direct signal of the transition to the insulating state. We demonstrate the utility of this method in our calculations for the Hubbard model on the hexagonal lattice. We also apply the method to the metal-insulator phase transition in the Hubbard-Coulomb model on the square lattice.


1973 ◽  
Vol 28 (5) ◽  
pp. 1111-1123 ◽  
Author(s):  
R. Sinclair ◽  
B. Ralph ◽  
J. A. Leake

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