Strong coupling of quantized spin waves in ferromagnetic bilayers

Tunable magnetically induced transparency spectra in magnon-magnon coupled Y3Fe5O12/permalloy bilayers

“…In order to verify the tunable coupling between the PSSW modes of YIG and the FMR mode of Py, micromagnetic simulations were performed to numerically solve the Landau-Lifshitz-Gilbert equation by using Mu-Max3 [31], with the effective magnetic field including contributions from the interlayer exchange field, the intralayer exchange field, the demagnetization field, and the external field. The strength of the interlayer exchange interaction between the YIG and the Py layers is deter- To excite PSSW modes in the YIG layer, a driving field h z (t) is locally applied in the bottommost layer of the Py along the z-axis [32]. The h z (t) is in the form of "sinc" function [33]: h z (t) = h 0 sin[2πf (t−t 0 )]/2πf (t−t 0 ), with the cut-off frequency f = 50 GHz, the offset time t 0 = 0.25 ns, and the amplitude h 0 = 1 mT.…”

“…Here, although using different g values for the V (H) fitting can in principle lead to an improved fitting result, we do not find a convincing k-dependent coupling g, which is also expected for the hybridized PSSW modes. This is because that the wavenumber of the PSSWs is primarily pointing out-of-plane, and the dipolar coupling between the PSSWs and the in-plane Py are sufficiently weak [32]. Besides, due to the large difference in the magnetization of YIG and Py, the PSSW modes that are actively coupled to the Py uniform mode are of higherindex (n ∼ 30 − 40), and their dipolar field is much less than the uniform mode and even those long wavelength (smaller n) PSSW modes [18].…”

Novel magnetic topological insulator FeBi2Te4 with controllable topological quantum phase

“…As shown in Fig. 1(e), compared to MBi 2 Te 4 (M = Mn, V, Ni, Eu) 5 and MnX 2 Y 4 (X = Sb, Bi, Y = Se, Te), 46 FeBi 2 Te 4 tends to present an FM order in the [100] direction, which is about 33.5 meV f.u. À1 lower than the AFM order.…”

“…42 Therefore, the topological magnetic research community has carried out research to enhance the temperature for realizing the QAHE. The observed temperature of the QAHE can be increased by doping, 7,8,[43][44][45][46][47][48][49][50][51][52][53] building magnetic insulator/topological insulator heterostructures, 38,[54][55][56][57][58] and applying external magnetic fields. 22,23,28,50 Sun et al established a topological phase diagram for triggering the QAHE by tuning the slab thickness and magnetization.…”

Investigating magnetic van der Waals materials using data-driven approaches

“…It should be noted that the monolayer Mn 2 Sb 4 S 8 and fewlayer Mn 2 Bi 4 Se 8 have been successfully synthesized in experiments. [69][70][71][72][73] While the monolayers of Mn 2 Bi 4 Se 8 , and Mn 2 Sb 4 Se 8 are predicted using first-principles calculations in the past, 74 the bulk phase of Mn 2 Bi 4 S 8 , and a quasi-onedimensional phase of Mn 2 Sb 4 Se 8 are also experimentally synthesized. 75,76 This supports the ability of DFT methods to discover novel materials.…”