Zero-temperature properties of quantum spin models on a triangular lattice I: the ferromagnet

1986 ◽  
Vol 64 (8) ◽  
pp. 876-881 ◽  
Author(s):  
S. Fujiki ◽  
D. D. Betts
Keyword(s):  
Triangular Lattice ◽  
Ground State ◽  
State Energy ◽  
Quantum Spin ◽  
Nearest Neighbour ◽  
Zero Temperature ◽  
Pair Correlations ◽  
Spin Correlations ◽  
Longitudinal Correlation ◽  
Quantum Spin Models

The calculation of two- and four-spin correlations of the [Formula: see text] ferromagnet has been extended to an N = 21 site triangular lattice. By fitting a quadratic in 1/N to the nearest neighbour transverse pair correlations, we have estimated the ground-state energy per bond on the infinite lattice to be E0/3NJ = −0.5326 ± 0.003. We conjecture that the square of the magnetization per site vanishes very sharply as N−0.06. The nearest neighbour longitudinal correlation per bond [Formula: see text] for all two-dimensional lattices.

Zero-temperature properties of quantum spin models on the triangular lattice II: the antiferromagnet

1987 ◽  
Vol 65 (1) ◽  
pp. 76-81 ◽  
Author(s):  
S. Fujiki ◽  
D. D. Betts
Keyword(s):  
Triangular Lattice ◽  
State Energy ◽  
Spin Correlation ◽  
Quantum Spin ◽  
Transverse Spin ◽  
Nearest Neighbour ◽  
Spin Correlations ◽  
Infinite Lattice ◽  
Longitudinal Correlation ◽  
Quantum Spin Models

The calculation of two- and four-spin correlations of the [Formula: see text] antiferromagnet has been extended to an N = 21 site triangular lattice. By fitting a quadratic in 1/N to the nearest neighbour transverse spin correlations, we have estimated the ground-state energy per bond on the infinite lattice to be E0/3NJ = −0.2716 ± 0.005. The nearest neighbour longitudinal correlation is estimated to be [Formula: see text]. A short-range order parameter, the chirality, is defined and estimated for the infinite lattice. From the N dependence of the three sublattice or helical magnetization, the spin correlation is conjectured to decay algebraically as [Formula: see text].

Zero-temperature properties of quantum spin models on the triangular lattice III: the Heisenberg antiferromagnet

1987 ◽  
Vol 65 (5) ◽  
pp. 489-491 ◽  
Author(s):  
S. Fujiki
Keyword(s):  
Triangular Lattice ◽  
Ground State ◽  
State Energy ◽  
Spin Correlation ◽  
Quantum Spin ◽  
Heisenberg Antiferromagnet ◽  
Zero Temperature ◽  
Spin Models ◽  
Spin Correlations ◽  
Quantum Spin Models

The calculation of two- and four-spin correlations of the [Formula: see text] Heisenberg antiferromagnet has been extended to an N = 21 site triangular lattice. The infinite-lattice ground state energy per bond is estimated to be E0/3NJ = −0.3678 ± 0.005 by fitting a quadratic in 1/N to the finite N data. The plaquette chirality order is slightly greater than in the XY antiferromagnet. The two-spin correlation is conjectured to decay as [Formula: see text].

COUPLED CLUSTER TREATMENTS OF QUANTUM MAGNETS: TWO EXAMPLES

2003 ◽  
Vol 17 (28) ◽  
pp. 5347-5365 ◽  
Author(s):  
SVEN E. KRÜGER ◽  
DAMIAN J. J. FARNELL ◽  
JOHANNES RICHTER
Keyword(s):  
Ground State ◽  
Quantum Monte Carlo ◽  
Quantum Spin ◽  
Square Lattice ◽  
Cluster Method ◽  
Coupled Cluster ◽  
Temperature Phase ◽  
Nearest Neighbour ◽  
Zero Temperature ◽  
Quantum Spin Models

In this article we study the ground-state properties of two square-lattice Heisenberg quantum spin models with competing bonds using a high-order coupled cluster treatment. The first model is a spin-half model with competing nearest-neighbour bonds with and without frustration. We discuss the influence of quantum fluctuations on the ground-state phase diagram and in particular on the nature of the zero-temperature phase transitions from phases with collinear magnetic order at small frustration to phases with noncollinear spiral order at large frustration. The second model is a highly frustrated ferrimagnet, which contains one sublattice (A) entirely populated with spin-one spins and an other sublattice (B) entirely populated with spin-half spins. Sublattice A sites are nearest-neighbours to sublattice B sites and vice versa and frustration is introduced by next-nearest-neighbour bonds. The model shows two collinear ordered phases and a noncollinear phase in which (classically) the spin-one spins are allowed to cant at an angle. Both examples show that the coupled-cluster method is able to describe the zero-temperature transitions well and provides a consistent description of collinear, noncollinear, and disordered phases, for cases in which other standard techniques (e.g. the quantum Monte Carlo technique for spin systems which are frustrated) are not applicable.

scholarly journals Field-induced instability of the quantum spin liquid ground state in the Jeff=12 triangular-lattice compound NaYbO2

2019 ◽  
Vol 99 (18) ◽  
Author(s):  
K. M. Ranjith ◽  
D. Dmytriieva ◽  
S. Khim ◽  
J. Sichelschmidt ◽  
S. Luther ◽  
...  
Keyword(s):  
Triangular Lattice ◽  
Ground State ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Spin Liquid

Electronic Excess Energy in Modulated Positive-Background Model

1982 ◽  
Vol 21 ◽  
Author(s):  
H. Yahauchi
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Electron Gas ◽  
Alloy System ◽  
Excess Energy ◽  
Absolute Zero ◽  
Background Model ◽  
Zero Temperature ◽  
Modulation Wavelength

ABSTRACTElectronic excess energy of a composition-modulated alloy system at absolute zero temperature is obtained using Hohenberg and Kohn's formula (for the ground-state energy of an inhomogeneous electron gas) in a modulated positive-background model. Dependence of the electronic excess energy on the modulation wavelength is studied. Two leading terms in the excess energy are examined to elucidate the limitation of this model.

Sign in / Sign up

Export Citation Format

Share Document