Propagating spin waves in nanometer-thick yttrium iron garnet films: Dependence on wave vector, magnetic field strength, and angle

Abstract

We present a comprehensive investigation of propagating spin waves in nanometer-thick yttrium iron garnet (YIG) films. We use broadband spin-wave spectroscopy with integrated coplanar waveguides (CPWs) and microstrip antennas on top of continuous and patterned YIG films to characterize spin waves with wave vectors up to 10 rad/µm. All films are grown by pulsed laser deposition. From spin-wave transmission spectra, parameters such as the Gilbert damping constant, spin-wave dispersion relation, group velocity, relaxation time, and decay length are derived and their dependence on magnetic bias field strength and angle is systematically gauged. For a 40-nm-thick YIG film, we obtain a damping constant of 3.5 × 10 −4 and a maximum decay length of 1.2 mm. Our experiments reveal a strong variation of spin-wave parameters with magnetic bias field and wave vector. Spinwave properties change considerably up to a magnetic bias field of about 30 mT and above a field angle of θH = 20 • , where θH = 0 • corresponds to the Damon-Eshbach configuration.

Chiral Spin-Wave Velocities Induced by All-Garnet Interfacial Dzyaloshinskii-Moriya Interaction in Ultrathin Yttrium Iron Garnet Films

“…4(d)] [37], which may result from the interfacial DMI. The spin-wave dispersions at 30 • become rather flat and therefore only a small group velocity v 0 g remains [37,42,43,50]. If the DMI-induced drift group velocity v DMI g ≈ v 0 g , the nonreciprocity is enhanced due to the interfacial DMI [37,51].…”

Electrical control of coherent spin rotation of a single-spin qubit

“…Figure 3c plots the characteristic wavevector spectrum. The well-defined excitation peaks are determined by the spatial distribution of the microwave fields generated by the CPW (see Supplementary Note 5) 35 . Figure 3d shows the ODMR map measured by the NV spin sensor, where up to four propagating surface spin wave modes with distinct wavevectors: k 1 , k 2 , k 3 , and k 4 emerge.…”

Propagation of Spin-Wave Packets in Individual Nanosized Yttrium Iron Garnet Magnonic Conduits

“…Space and time resolved micro-focused Brillouin-Light-Scattering (BLS) spectroscopy is used to extract the exchange constant and directly measure the spin-wave decay length and group velocity. Thereby, the first experimental proof of propagating spin waves in individual nano-sized YIG conduits and the fundamental feasibility of a nano-scaled magnonics are demonstrated.State of the art investigations are typically performed in micron-sized structures [13][14][15] lacking the final push to the nanoscale and are often based on the so-called Damon-Eshbach (DE) geometry, since this geometry provides a high spin-wave group velocity [16]. However, large bias magnetic fields are required to achieve the corresponding magnetization state in nano-sized conduits.…”

“…State of the art investigations are typically performed in micron-sized structures [13][14][15] lacking the final push to the nanoscale and are often based on the so-called Damon-Eshbach (DE) geometry, since this geometry provides a high spin-wave group velocity [16]. However, large bias magnetic fields are required to achieve the corresponding magnetization state in nano-sized conduits.…”