Magnetic anisotropy and GGG substrate stray field in YIG films down to millikelvin temperatures

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F26%3A0196778" target="_blank" >RIV/00216305:26620/26:0196778 - isvavai.cz</a>

Result on the web

<a href="https://www.nature.com/articles/s44306-024-00030-7" target="_blank" >https://www.nature.com/articles/s44306-024-00030-7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s44306-024-00030-7" target="_blank" >10.1038/s44306-024-00030-7</a>

Result language

angličtina

Original language name

Magnetic anisotropy and GGG substrate stray field in YIG films down to millikelvin temperatures

Original language description

Quantum magnonics investigates the quantum-mechanical properties of magnons, such as quantum coherence or entanglement for solid-state quantum information technologies at the nanoscale. The most promising material for quantum magnonics is the ferrimagnetic yttrium iron garnet (YIG), which hosts magnons with the longest lifetimes. YIG films of the highest quality are grown on a paramagnetic gadolinium gallium garnet (GGG) substrate. The literature has reported that ferromagnetic resonance (FMR) frequencies of YIG/GGG decrease at temperatures below 50 K despite the increase in YIG magnetization. We investigated a 97 nm-thick YIG film grown on 500 μm-thick GGG substrate through a series of experiments conducted at temperatures as low as 30 mK, and using both analytical and numerical methods. Our findings suggest that the primary factor contributing to the FMR frequency shift is the stray magnetic field created by the partially magnetized GGG substrate. This stray field is antiparallel to the applied external field and is highly inhomogeneous, reaching up to 40 mT in the center of the sample. At temperatures below 500 mK, the GGG field exhibits a saturation that cannot be described by the standard Brillouin function for a paramagnet. Including the calculated GGG field in the analysis of the FMR frequency versus temperature dependence allowed the determination of the cubic and uniaxial anisotropies. We find that the total crystallographic anisotropy increases more than three times with the decrease in temperature down to 2 K. Our findings enable accurate predictions of the YIG/GGG magnetic systems behavior at low and ultralow millikelvin temperatures, crucial for developing quantum magnonic devices.

Czech name

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Czech description

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Type

J_SC - Article in a specialist periodical, which is included in the SCOPUS database

CEP classification

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OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

npj spintronics

ISSN

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e-ISSN

2948-2119

Volume of the periodical

2

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

7

Pages from-to

1-7

UT code for WoS article

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EID of the result in the Scopus database

2-s2.0-105010963734