Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userElectron spin resonance in a model S=1/2 chain antiferromagnet with a uniform Dzyaloshinskii--Moriya interaction
421
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The electron spin resonance spectrum of a quasi 1D S=1/2 antiferromagnet K2CuSO4Br2 was found to demonstrate an energy gap and a doublet of resonance lines in a wide temperature range between the Curie--Weiss and Ne`{e}l temperatures. This type of magnetic resonance absorption corresponds well to the two-spinon continuum of excitations in S=1/2 antiferromagnetic spin chain with a uniform Dzyaloshinskii--Moriya interaction between the magnetic ions. A resonance mode of paramagnetic defects demonstrating strongly anisotropic behavior due to interaction with spinon excitations in the main matrix is also observed.
rate research
Read More
We study the thermodynamics of an XYZ Heisenberg chain with Dzyaloshinskii-Moriya interaction, which describes the low-energy behaviors of a one-dimensional spin-orbit-coupled bosonic model in the deep insulating region. The entropy and the specific heat are calculated numerically by the quasi-exact transfer-matrix renormalization group. In particular, in the limit $U^prime/Urightarrowinfty$, our model is exactly solvable and thus serves as a benchmark for our numerical method. From our data, we find that for $U^prime/U>1$ a quantum phase transition between an (anti)ferromagnetic phase and a Tomonaga-Luttinger liquid phase occurs at a finite $theta$, while for $U^prime/U<1$ a transition between a ferromagnetic phase and a paramagnetic phase happens at $theta=0$. A refined ground-state phase diagram is then deduced from their low-temperature behaviors. Our findings provide an alternative way to detect those distinguishable phases experimentally.
We have investigated the electron spin resonance (ESR) on single crystals of BaCu$_2$Ge$_2$O$_7$ at temperatures between 300 and 2 K and in a large frequency band, 9.6 -134 GHz, in order to test the predictions of a recent theory, proposed by Oshikawa and Affleck (OA), which describes the ESR in a $S$=1/2 Heisenberg chain with the Dzyaloshinskii-Moriya interaction. We find, in particular, that the ESR linewidth, $Delta H$, displays a rich temperature behavior. As the temperature decreases from $T_{max}/2approx $ 170 K to 50 K, $Delta H$ shows a rapid and linear decrease, $Delta H sim T$. At low temperatures, below 50 K, $Delta H$ acquires a strong dependence on the magnetic field orientation and for $H | c$ it shows a $(h/T)^2$ behavior which is due to an induced staggered field $h$, according to OAs prediction.
We report a combined analytical and density matrix renormalized group study of the antiferromagnetic XXZ spin-1/2 Heisenberg chain subject to a uniform Dzyaloshinskii-Moriya (DM) interaction and a transverse magnetic field. The numerically determined phase diagram of this model, which features two ordered Ising phases and a critical Luttinger liquid one with fully broken spin-rotational symmetry, agrees well with the predictions of Garate and Affleck [Phys. Rev. B 81, 144419 (2010)]. We also confirm the prevalence of the N z Neel Ising order in the regime of comparable DM and magnetic field magnitudes.
We study the magnetic properties of the two-dimensional anisotropic antiferromagnetic spin-1/2 Heisenberg model with Dzyaloshinskii-Moriya interaction and in-plane frustration included. The method of spin Green functions within the framework of Tyablikovs random-phase-approximation decoupling scheme is used in order to derive expressions for the spin-wave spectrum, sublattice magnetization and transition temperature. Based on these expressions we perform a detailed analysis of the influence of varying values of model parameters on its magnetic properties. The model is also applied to the high-Tc superconducting parent compound La2Cuo4 and our results compared to available experimental data.
Thermodynamic properties of the S=1/2 Heisenberg chain in transverse staggered magnetic field H^y_s and uniform magnetic field H^x perpendicular to the staggered field is studied by the finite-temperature density-matrix renormalization-group method. The uniform and staggered magnetization and specific heat are calculated from zero temperature to high temperatures up to T/J=4 under various strength of magnetic fields from H^y_s/J, H^x/J=0 to 2.4. The specific heat and magnetization of the effective Hamiltonian of the Yb_4As_3 are also presented, and field induced gap formation and diverging magnetic susceptibility at low temperature are shown.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
