Exact diagonalization study of the frustrated Heisenberg model: A new disordered phase

1989 ◽  
Vol 39 (7) ◽  
pp. 4744-4747 ◽  
Author(s):  
E. Dagotto ◽  
A. Moreo
Keyword(s):  
Heisenberg Model ◽  
Exact Diagonalization ◽  
Disordered Phase

scholarly journals EVIDENCE OF A SPIN-LIQUID PHASE IN THE FRUSTRATED HONEYCOMB LATTICE

2011 ◽  
Vol 25 (12n13) ◽  
pp. 891-900 ◽  
Author(s):  
D. C. CABRA ◽  
C. A. LAMAS ◽  
H. D. ROSALES
Keyword(s):  
Liquid Phase ◽  
Heisenberg Model ◽  
Short Range ◽  
Intermediate Phase ◽  
Mean Field ◽  
Exact Diagonalization ◽  
Quantum Limit ◽  
Honeycomb Lattice ◽  
Spin Liquid ◽  
Disordered Phase

In the present paper, we present some new data supporting the existence of a spin-disordered phase in the Heisenberg model on the honeycomb lattice with antiferromagnetic interactions up to third neighbors along the line J2 = J3, predicted in Ref. 1. We use the Schwinger boson technique followed by a mean field decoupling and exact diagonalization for small systems to show the existence of an intermediate phase with a spin gap and short range Néel correlations in the strong quantum limit [Formula: see text].

scholarly journals Critical colored-RVB states in the frustrated quantum Heisenberg model on the square lattice

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Didier Poilblanc ◽  
Matthieu Mambrini ◽  
Sylvain Capponi
Keyword(s):  
Correlation Length ◽  
Heisenberg Model ◽  
Valence Bond ◽  
Spin Correlation ◽  
Square Lattice ◽  
Spin Liquid ◽  
Disordered Phase ◽  
Resonating Valence Bond ◽  
Dimer Models

We consider a family of SU(2)-symmetric Projected Entangled Paired States (PEPS) on the square lattice, defining colored-Resonating Valence Bond (RVB) states, to describe the quantum disordered phase of the J_1-J_2J1−J2 frustrated Heisenberg model. For J_2/J_1\sim 0.55J2/J1∼0.55 we show the emergence of critical (algebraic) dimer-dimer correlations – typical of Rokhsar-Kivelson (RK) points of quantum dimer models on bipartite lattices – while, simultaneously, the spin-spin correlation length remains short. Our findings are consistent with a spin liquid or a weak Valence Bond Crystal in the neighborhood of an RK point.

Antiphase Boundaries in Ordered Ni3FE Crystals

1969 ◽  
Vol 27 ◽  
pp. 62-63
Author(s):  
Y. H. Liu
Keyword(s):  
Domain Size ◽  
Antiphase Domain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardening Mechanism ◽  
Superlattice Structure ◽  
Disordered Phase ◽  
Domain Boundaries ◽  
Atomic Scattering ◽  
The Difference

Ordered Ni3Fe crystals possess a LI2 type superlattice similar to the Cu3Au structure. The difference in slip behavior of the superlattice as compared with that of a disordered phase has been well established. Cottrell first postulated that the increase in resistance for slip in the superlattice structure is attributed to the presence of antiphase domain boundaries. Following Cottrell's domain hardening mechanism, numerous workers have proposed other refined models also involving the presence of domain boundaries. Using the anomalous X-ray diffraction technique, Davies and Stoloff have shown that the hardness of the Ni3Fe superlattice varies with the domain size. So far, no direct observation of antiphase domain boundaries in Ni3Fe has been reported. Because the atomic scattering factors of the elements in NijFe are so close, the superlattice reflections are not easily detected. Furthermore, the domain configurations in NioFe are thought to be independent of the crystallographic orientations.

Ordering in Ni4Mo by TEM and APFIM

1987 ◽  
Vol 45 ◽  
pp. 214-215
Author(s):  
E.A. Kenik ◽  
T.A. Zagula ◽  
M.K. Miller ◽  
J. Bentley
Keyword(s):  
Electron Irradiation ◽  
Low Temperatures ◽  
Short Range ◽  
Atom Probe ◽  
Range Order ◽  
Considerable Time ◽  
Probe Field ◽  
Disordered Phase ◽  
Transmission Electron ◽  
Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

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