اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMicrowave photovoltage and photoresistance effects in ferromagnetic microstrips
159
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We investigate the dc electric response induced by ferromagnetic resonance in ferromagnetic Permalloy (Ni80Fe20) microstrips. The resulting magnetization precession alters the angle of the magnetization with respect to both dc and rf current. Consequently the time averaged anisotropic magnetoresistance (AMR) changes (photoresistance). At the same time the time-dependent AMR oscillation rectifies a part of the rf current and induces a dc voltage (photovoltage). A phenomenological approach to magnetoresistance is used to describe the distinct characteristics of the photoresistance and photovoltage with a consistent formalism, which is found in excellent agreement with experiments performed on in-plane magnetized ferromagnetic microstrips. Application of the microwave photovoltage effect for rf magnetic field sensing is discussed.
قيم البحث
اقرأ أيضاً
The temperature dependence of microwave-induced resistance oscillations (MIRO), according to the theory, originates from electron-electron scattering. This scattering affects both the quantum lifetime, or the density of states, and the inelastic life
time, which governs the relaxation of the nonequilibrium distribution function. Here, we report on MIRO in an ultrahigh mobility ($mu > 3 times 10^7$ cm$^2$/Vs) 2D electron gas at $T$ between $0.3$ K and $1.8$ K. In contrast to theoretical predictions, the quantum lifetime is found to be $T$-independent in the whole temperature range studied. At the same time, the $T$-dependence of the inelastic lifetime is much emph{stronger} than can be expected from electron-electron interactions.
We use a numerical electromagnetic simulation software to investigate a filtering device consisting of a small dimensional microstrips embedded with a thin layer of ferromagnetic material and we compare our results to experimental results. We are abl
e to show good correlation of simulation versus experiment for the magnitude of insertion loss and phase shift. The microstrips considered have dimensions on the order of the skin depth of the conductor and hence the field distribution is not easily calculated by analytic methods. We show that numerical simulation methods provide an accurate means of characterizing these structures.
The electronic band structure of bulk ferromagnetic iron is explored by angle-resolved photoemission for electron correlation effects. Fermi surface cross-sections as well as band maps are contrasted with density functional calculations. The Fermi ve
ctors and band parameters obtained from photoemission and their prediction from band theory are analyzed in detail. Generally good agreement is found for the Fermi surface. A bandwidth reduction for shallow bands of ~ 30 % is observed. Additional strong quasiparticle renormalization effects are found near the Fermi level, leading to a considerable mass enhancement. The role of electronic correlation effects and the electronic coupling to magnetic excitations is discussed in view of the experimental results.
The microwave photoresistance of a two-dimensional topological insulator in a HgTe quantum well with an inverted spectrum has been experimentally studied under irradiation at frequencies of 110-169 GHz. Two mechanisms of formation of this photoresist
ance have been revealed. The first mechanism is due to transitions between the dispersion branches of edge current states, whereas the second mechanism is caused by the action of radiation on the bulk of the quantum well.
A spin model including magnetic anisotropy terms and Dzyaloshinsky-Moriya interactions is studied for the case of a ferromagnetic monolayer with C2v symmetry like Fe/W(110). Using the quasiclassical stochastic Landau-Lifshitz-Gilbert equations, the m
agnon spectrum of the system is derived using linear response theory. The Dzyaloshinsky-Moriya interaction leads to asymmetry in the spectrum, while the anisotropy terms induce a gap. It is shown that in the presence of lattice defects, both the Dzyaloshinsky-Moriya interactions and the two-site anisotropy lead to a softening of the magnon energies. Two methods are developed to investigate the magnon spectrum at finite temperatures. The theoretical results are compared to atomistic spin dynamics simulations and a good agreement is found between them.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
