A two-dimensional Heisenberg S = 1 antiferromagnet with exchange interactions of two types on a hexagonal lattice: RSRG and DMRG analyses

2005 ◽  
Vol 101 (3) ◽  
pp. 472-480
Author(s):  
V. E. Sinitsyn ◽  
A. S. Boyarchenkov ◽  
A. S. Ovchinnikov ◽  
I. G. Bostrem
2021 ◽  
Vol 63 (5) ◽  
pp. 622
Author(s):  
А.К. Муртазаев ◽  
М.К. Мазагаева ◽  
М.К. Рамазанов ◽  
М.А. Магомедов ◽  
А.А. Муртазаева

We have carried out Monte Carlo investigations of the phase transitions, thermodynamic properties and ground-state magnetic structures in two-dimensional 4-state Potts model on a hexagonal lattice with the competing exchange interactions. Researches are carried out for the value of interaction of next-nearest neighbor in the range of 0.0≤r≤1.0. Taking into account of antiferromagnetic interaction of next-nearest neighbor is shown to lead to the violation of the magnetic ordering. The phase diagram of dependence of critical temperature on the value of interaction of next-nearest neighbor is plotted. Of the orders of phase transitions has been carried out. It is established that the phase transition of the first order is observed in the ranges of 0.0≤r≤0.2 and 0.7≤r≤1.0. In the range of 0.3≤r≤0.6 frustration are observed.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yung-Chang Lin ◽  
Sungwoo Lee ◽  
Yueh-Chiang Yang ◽  
Po-Wen Chiu ◽  
Gun-Do Lee ◽  
...  

AbstractInterhalogen compounds (IHCs) are extremely reactive molecules used for halogenation, catalyst, selective etchant, and surface modification. Most of the IHCs are unstable at room temperature especially for the iodine-monofluoride (IF) whose structure is still unknown. Here we demonstrate an unambiguous observation of two-dimensional (2D) IF bilayer grown on the surface of WSe2 by using scanning transmission electron microscopy and electron energy loss spectroscopy. The bilayer IF shows a clear hexagonal lattice and robust epitaxial relationship with the WSe2 substrate. Despite the IF is known to sublimate at −14 °C and has never found as a solid form in the ambient condition, but surprisingly it is found stabilized on a suitable substrate and the stabilized structure is supported by a density functional theory. This 2D form of IHC is actually a byproduct during a chemical vapor deposition growth of WSe2 in the presence of alkali metal halides as a growth promoter and requires immediate surface passivation to sustain. This work points out a great possibility to produce 2D structures that are unexpected to be crystallized or cannot be obtained by a simple exfoliation but can be grown only on a certain substrate.


1992 ◽  
Vol 296 ◽  
Author(s):  
Robert S. Sinkovits ◽  
Lee Phillips ◽  
Elaine S. Oran ◽  
Jay P. Boris

AbstractThe interactions of shocks with defects in two-dimensional square and hexagonal lattices of particles interacting through Lennard-Jones potentials are studied using molecular dynamics. In perfect lattices at zero temperature, shocks directed along one of the principal axes propagate through the crystal causing no permanent disruption. Vacancies, interstitials, and to a lesser degree, massive defects are all effective at converting directed shock motion into thermalized two-dimensional motion. Measures of lattice disruption quantitatively describe the effects of the different defects. The square lattice is unstable at nonzero temperatures, as shown by its tendency upon impact to reorganize into the lower-energy hexagonal state. This transition also occurs in the disordered region associated with the shock-defect interaction. The hexagonal lattice can be made arbitrarily stable even for shock-vacancy interactions through appropriate choice of potential parameters. In reactive crystals, these defect sites may be responsible for the onset of detonation. All calculations are performed using a program optimized for the massively parallel Connection Machine.


1994 ◽  
Vol 49 (1) ◽  
pp. 44-54 ◽  
Author(s):  
Robb Thomson ◽  
S. J. Zhou

1990 ◽  
Vol 59 (5) ◽  
pp. 1792-1800 ◽  
Author(s):  
Masayuki Itoh ◽  
Isao Yamada ◽  
Mamoru Ishizuka ◽  
Kiichi Amaya ◽  
Tatsuo Kobayashi ◽  
...  

Author(s):  
H. Rattanasonti ◽  
P. Srinivasan ◽  
M. Kraft ◽  
R. C. Sterling ◽  
S. Weidt ◽  
...  

2013 ◽  
Vol 79 (5) ◽  
pp. 629-633
Author(s):  
B. FAROKHI

AbstractThe linear dust lattice waves propagating in a two-dimensional honeycomb configuration is investigated. The interaction between particles is considered up to distance 2a, i.e. the third-neighbor interactions. Longitudinal and transverse (in-plane) dispersion relations are derived for waves in arbitrary directions. The study of dispersion relations with more neighbor interactions shows that in some cases the results change physically. Also, the dispersion relation in the different direction displays anisotropy of the group velocity in the lattice. The results are compared with dispersion relations of the waves in the hexagonal lattice.


2018 ◽  
Vol 9 ◽  
pp. 2668-2673 ◽  
Author(s):  
José Carlos Abadillo-Uriel ◽  
Belita Koiller ◽  
María José Calderón

Since the proposal in 1998 to build a quantum computer using dopants in silicon as qubits, much progress has been made in the nanofabrication of semiconductors and the control of charge and spins in single dopants. However, an important problem remains unsolved, namely the control over exchange interactions and tunneling between two donors, which presents a peculiar oscillatory behavior as the dopants relative positions vary at the scale of the lattice parameter. Such behavior is due to the valley degeneracy in the conduction band of silicon, and does not occur when the conduction-band edge is at k = 0. We investigate the possibility of circumventing this problem by using two-dimensional (2D) materials as hosts. Dopants in 2D systems are more tightly bound and potentially easier to position and manipulate. Moreover, many of them present the conduction band minimum at k = 0, thus no exchange or tunnel coupling oscillations. Considering the properties of currently available 2D semiconductor materials, we access the feasibility of such a proposal in terms of quantum manipulability of isolated dopants (for single qubit operations) and dopant pairs (for two-qubit operations). Our results indicate that a wide variety of 2D materials may perform at least as well as, and possibly better, than the currently studied bulk host materials for donor qubits.


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