ترغب بنشر مسار تعليمي؟ اضغط هنا

Thermal Hall Effect of Chiral Spin Fluctuations

340   0   0.0 ( 0 )
 نشر من قبل Caitlin Carnahan
 تاريخ النشر 2021
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Using a two-dimensional square lattice Heisenberg model with a Rashba-type Dzyaloshinskii-Moriya interaction, we demonstrate that chiral spin fluctuations can give rise to a thermal Hall effect in the absence of any static spin texture or momentum space topology. It is shown by means of Monte Carlo and stochastic spin dynamics simulations that the thermal Hall response is finite at elevated temperature outside of the linear spin wave regime and consistent with the presence of thermal fluctuation-induced nontrivial topology. Our result suggests that the high-fluctuation phases outside of the conventional regime of magnonics may yet be a promising area of exploration for spin-based electronics.



قيم البحث

اقرأ أيضاً

119 - Hantao Zhang , Ran Cheng 2020
In an easy-plane antiferromagnet with the Dzyaloshinskii-Moriya interaction (DMI), magnons are subject to an effective spin-momentum locking. An in-plane temperature gradient can generate interfacial accumulation of magnons with a specified polarizat ion, realizing the magnon thermal Edelstein effect. We theoretically investigate the injection and detection of this thermally-driven spin polarization in an adjacent heavy metal with strong spin Hall effect. We find that the inverse spin Hall voltage depends monotonically on both temperature and the DMI but non-monotonically on the hard-axis anisotropy. Counterintuitively, the magnon thermal Edelstein effect is an even function of a magnetic field applied along the Neel vector.
We predict an anomalous thermal Hall effect (ATHE) mediated by photons in networks of Weyl semi-metals. Contrary to the photon thermal Hall effect in magneto-optical systems which requires the application of an external magnetic field the ATHE in a W eyl semi-metals network is an intrinsic property of these systems. Since the Weyl semi-metals can exhibit a strong nonreciprocal response in the infrared over a broad spectral range the magnitude of thermal Hall flux in these systems can be relatively large compared to the primary flux. This ATHE paves the way for a directional control of heat flux by localy tuning the magnitude of temperature field without changing the direction of temperature gradient.
A strategy to drive skyrmion motion by a combination of an anisotropy gradient and spin Hall effect has recently been demonstrated. Here, we study the fundamental properties of this type of motion by combining micromagnetic simulations and a generali zed Thiele equation. We find that the anisotropy gradient drives the skyrmion mainly along the direction perpendicular to the gradient, due to the conservative part of the torque. There is some slower motion along the direction parallel to the anisotropy gradient due to damping torque. When an appropriate spin Hall torque is added, the skyrmion velocity in the direction of the anisotropy gradient can be enhanced. This motion gives rise to acceleration of the skyrmion as this moves to regions of varying anisotropy. This phenomenon should be taken into account in experiments for the correct evaluation of the skyrmion velocity. We employ a Thiele like formalism and derive expressions for the velocity and the acceleration of the skyrmion that match very well with micromagnetic simulation results.
Spin transistors and spin Hall effects have been two separate leading directions of research in semiconductor spintronics which seeks new paradigms for information processing technologies. We have brought the two directions together to realize an all -semiconductor spin Hall effect transistor. Our scheme circumvents semiconductor-ferromagnet interface problems of the original Datta-Das spin transistor concept and demonstrates the utility of the spin Hall effects in microelectronics. The devices use diffusive transport and operate without electrical current, i.e., without Joule heating in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our experimental study is complemented by numerical Monte Carlo simulations of spin-diffusion through the transistor channel.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا