Added Dzyaloshinskii-Moriya Interaction Research Articles

Effect of Dzyaloshinskii-Moriya Interaction on Heisenberg Antiferromagnetic Spin Chain in the Presence of a Longitudinal Magnetic Field

Using functional integral method for the Heisenberg antiferromagnetic spin chain with the added Dzyaloshinskii-Moriya Interaction in the presence of the longitudinal magnetic field, we find out expression for free energy of the spin chain via spin fluctuations, from which quantities characterize the antiferromagnetic order and phase transition such as staggered and total magnetizations derived. From that, we deduce the significant effect of the Dzyaloshinskii-Moriya interaction on the reduction of the antiferromagnetic order and show that the total magnetization can be deviated from the initial one under the influence of canting of the spins due to a combination of the Dzyaloshinskii-Moriya interaction and the magnetic field. Besides, the remarkable role of the transverse spin fluctuations due to the above factors on the antiferromagnetic behaviours of the spin chain is also indicated.

Q = 0 order in quantum kagome Heisenberg antiferromagnet

We have studied the nearest neighbor Heisenberg model with added Dzyaloshinskii–Moriya interaction using Schwinger boson mean-field theory considering the in-plane component as well as out-of-plane component. Motivated by the experimental result of vesignieite that the ground state is in a Q = 0 long-range order state, we first looked at the classical ground state of the model and considered the mean-field ansatz which mimics the classical ground state in the large S limit. We have obtained the ground-state phase diagram of this model and calculated properties of different phases. We have also studied the above model numerically using exact diagonalization up to a system size N = 30. We have compared the obtained results from these two approaches. Our results are in agreement with the experimental result of the vesignieite.

Total Pairwise Quantum Correlation and Entanglement in a Mixed-Three-Spin Ising-XY Model with Added Dzyaloshinskii—Moriya Interaction under Decoherence

We investigate the behavior of geometric global quantum discord (GGQD) and concurrence (C) between half-spins of a mixed-three-spin (1/2, 1, 1/2) system with the Ising-XY model for which spins (1, 1/2) have the Ising interaction and half-spins (1/2, 1/2) have both XY and the Dzyaloshinskii—Moriya interactions together, under the decoherence action. A single-ion anisotropy property with coefficient ζ is assumed for the spin-integer. This system which includes an analytical Hamiltonian is considered at the front of an external homogeneous magnetic field B in thermal equilibrium. Finally, we compare GGQD and C and express some interesting phase flip reactions of the total quantum correlation and pairwise entanglement between spins (1/2, 1/2). Generally, we conclude that the concurrence and GGQD have different behaviors under the phase flip channel.

Quantum correlations in the 1D spin-1/2 Ising model with added Dzyaloshinskii–Moriya interaction

We have considered the 1D spin-1/2 Ising model with added Dzyaloshinskii–Moriya (DM) interaction and presence of a uniform magnetic field. Using the mean-field fermionization approach the energy spectrum in an infinite chain is obtained. The quantum discord (QD) and concurrence between nearest neighbor (NN) spins at finite temperature are specified as a function of mean-field order parameters. A comparison between concurrence and QD is done and differences are obtained. The macroscopic thermodynamical witness is also used to detect quantum entanglement region in solids within our model. We believe our results are useful in the field of the quantum information processing.

Quantum Correlations in Three-Qubit Ising Model with Added Dzyaloshinskii–Moriya Interaction

The thermal behavior of the quantum correlations in a three-qubit Ising model with added Dzyaloshinskii–Moriya (DM) interaction is studied. Quantum correlations are calculated in the three-qubit system through symmetric (SY) and nonsymmetric (NYS) ways. In particular, the study is focused on the concurrence (C) and the quantum discord (QD). Intriguing results are found by comparing the finite-temperature results with the ground-state results. Especially, an opposite trend of the ground state QD and C through both SY and NSY ways is found. The thermal behavior of the C (TC) through the SY way is shown to be a robust trend against thermal fluctuations. Two kinds of zero and nonzero plateau behavior in the thermal QD curve are also found. The width of the QD plateau is calculated, and it is found that it scales as D e , where the critical exponent varies from e=0.5 in the antiferromagnetic case to e=−0.6 in the ferromagnetic case.

Specific Heat of the 1D Spin-1/2 Ising Model with Added Dzyaloshinskii–Moriya Interaction

The 1D spin-1/2 Ising model in a uniform magnetic field with added the Dzyaloshinskii–Moriya (DM) interaction is considered. The energy spectrum is obtained using the fermionization approach and defining some mean field order parameters. Then the specific heat is determined in an infinite chain system. Results show that there is only one peak in the specific heat as a function of the temperature. In the Neel phase, the position of the peak is found almost field-independent, but the maximum value of the specific heat decreases by increasing the magnetic field. Also, in the region of the saturated ferromagnetic phase, by increasing h, the peak becomes wider and goes to higher temperatures, which is a signal for the saturated ferromagnetic phase. In addition, the specific heat at low temperature shows two peaks structure on both sides of the quantum critical point.

1D frustrated ferromagnetic model with added Dzyaloshinskii-Moriya interaction

The one-dimensional (1D) isotropic frustrated ferromagnetic spin-1/2 model is considered. Classical and quantum effects of adding a Dzyaloshinskii-Moriya (DM) interaction on the ground state of the system is studied using the analytical cluster method and numerical Lanczos technique. Cluster method results, show that the classical ground state magnetic phase diagram consists of only one single phase: "chiral". The quantum corrections are determined by means of the Lanczos method and a rich quantum phase diagram including the gapless Luttinger liquid, the gapped chiral and dimer orders is obtained. Moreover, next nearest neighbors will be entangled by increasing DM interaction and for open chains, end-spins are entangled which shows the long distance entanglement (LDE) feature that can be controlled by DM interaction.

Entanglement Study of the 1D Ising Model with Added Dzyaloshinskii–Moriya Interaction

We have studied occurrence of quantum phase transition in the one-dimensional spin-1/2 Ising model with added Dzyaloshinsky-Moriya (DM) interaction from bi- partite and multi-partite entanglement point of view. Using exact numerical solutions, we are able to study such systems up to 24 qubits. The minimum of the entanglement ratio R $\equiv$ \tau 2/\tau 1 < 1, as a novel estimator of QPT, has been used to detect QPT and our calculations have shown that its minimum took place at the critical point. We have also shown both the global-entanglement (GE) and multipartite entanglement (ME) are maximal at the critical point for the Ising chain with added DM interaction. Using matrix product state approach, we have calculated the tangle and concurrence of the model and it is able to capture and confirm our numerical experiment result. Lack of inversion symmetry in the presence of DM interaction stimulated us to study entanglement of three qubits in symmetric and antisymmetric way which brings some surprising results.

Heisenberg Model with Added Dzyaloshinskii-Moria Interaction

We have considered the 1D spin-(1/2) Heisenberg model with added Dzyaloshinskii-Moriya interaction. The effect of a uniform magnetic field on the ground state phase diagram of the model is studied. We have mapped the model to an effective model which is known as the 1D XXZ in both uniform and staggered magnetic fields. By selecting a block of two or three spins, we have solved the Hamiltonian exactly. Our results show that the quantum phase transitions can be obtained from the block of pair or three spins.