scholarly journals Dynamics of magnetic collective modes in square- and triangular-lattice Mott insulators at finite temperature

2021 ◽  
Vol 104 (23) ◽  
Author(s):  
Sauri Bhattacharyya ◽  
Pinaki Majumdar
Keyword(s):  
Triangular Lattice ◽  
Finite Temperature ◽  
Collective Modes ◽  
Mott Insulators

scholarly journals Is there a phase transition in the isotropic Heisenberg anti-ferromagnet on the triangular lattice?

2001 ◽  
Vol 79 (11-12) ◽  
pp. 1459-1461 ◽  
Author(s):  
W Stephan ◽  
B W Southern
Keyword(s):  
Phase Transition ◽  
Triangular Lattice ◽  
Finite Temperature ◽  
Easy Axis ◽  
Temperature Phase ◽  
Temperature Transition ◽  
Isotropic Model ◽  
Temperature Phase Transition ◽  
Lower Temperature ◽  
Xxz Heisenberg Model

The phase diagram of the classical anisotropic (XXZ) Heisenberg model on the two-dimensional triangular lattice is investigated using Monte Carlo methods. In the easy-axis limit, two finite-temperature vortex-unbinding transitions have been observed. In the easy-plane limit, there also appear to be two distinct finite-temperature phase transitions that are very close in temperature. The upper transition corresponds to an Ising-like chirality ordering and the lower temperature transition corresponds to a Kosterlitz–Thouless vortex-unbinding transition. These phase-transition lines all meet at the Heisenberg point and provide strong evidence that the isotropic model undergoes a novel finite-temperature phase transition. PACS Nos.: 75.10Hk, 75.40Mg

scholarly journals Spin wave theory of spin-1/2 XY model with ring exchange on a triangular lattice

2013 ◽  
Vol 91 (7) ◽  
pp. 542-547 ◽  
Author(s):  
Solomon A. Owerre
Keyword(s):  
Phase Transition ◽  
Spin Wave ◽  
Triangular Lattice ◽  
Finite Temperature ◽  
Wave Theory ◽  
Square Lattice ◽  
Xy Model ◽  
Superfluid Phase ◽  
Zero Temperature ◽  
Ring Exchange

We present the linear spin wave theory calculation of the superfluid phase of a hard-core boson J-K model with nearest neighbour exchange J and four-particle ring-exchange K at half filling on the triangular lattice, as well as the phase diagrams of the system at zero and finite temperatures. A similar analysis has been done on a square lattice (Schaffer et al. Phys. Rev. B, 80, 014503 (2009)). We find similar behaviour to that of a square lattice but with different spin wave values of the thermodynamic quantities. We also find that the pure J model (XY model), which has a well-known uniform superfluid phase with an ordered parameter [Formula: see text] at zero temperature is quickly destroyed by the inclusion of negative-K ring-exchange interactions, favouring a state with a (4π/3, 0) ordering wavevector. We further study the behaviour of the finite-temperature Kosterlitz–Thouless phase transition (TKT) in the uniform superfluid phase, by forcing the universal quantum jump condition on the finite-temperature spin wave superfluid density. We find that for K < 0, the phase boundary monotonically decreases to T = 0 at K/J = −4/3, where a phase transition is expected and TKT decreases rapidly, while for positive K, TKT reaches a maximum at some K ≠ 0. It has been shown on a square lattice using quantum Monte Carlo (QMC) simulations that for small K > 0 away from the XY point, the zero-temperature spin stiffness value of the XY model is decreased (Melko and Sandvik. Ann. Phys. 321, 1651 (2006)). Our result seems to agree with this trend found in QMC simulations for two-dimensional systems.

Simulation of collective modes at finite temperature

2009 ◽  
pp. 256-291
Author(s):  
Allan Griffin ◽  
Tetsuro Nikuni ◽  
Eugene Zaremba
Keyword(s):  
Finite Temperature ◽  
Collective Modes

Quantum phases of electron double layers: soft collective modes and finite-temperature phase transitions

2000 ◽  
Vol 6 (1-4) ◽  
pp. 573-576
Author(s):  
Vittorio Pellegrini ◽  
Aron Pinczuk ◽  
Brian S Dennis ◽  
Loren N Pfeiffer ◽  
Ken W West
Keyword(s):  
Phase Transitions ◽  
Finite Temperature ◽  
Double Layers ◽  
Collective Modes ◽  
Temperature Phase ◽  
Quantum Phases

Heat jet approach for finite temperature atomic simulations of triangular lattice

2017 ◽  
Vol 59 (5) ◽  
pp. 843-859 ◽  
Author(s):  
Baiyili Liu ◽  
Shaoqiang Tang ◽  
Jun Chen
Keyword(s):  
Triangular Lattice ◽  
Finite Temperature ◽  
Atomic Simulations
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