Thermodynamics of free and bound magnons in graphene
Name
s41567-021-01421-x.pdf
Description
Published version
Size
4.5 MB
Format
Adobe PDF
Checksum (MD5)
762607ab5f47b4d61f64ccb1749a03ee
Author(s)
Pierce, Andrew T
Xie, Yonglong
Lee, Seung Hwan
Forrester, Patrick R
Wei, Di S
Watanabe, Kenji
Taniguchi, Takashi
Halperin, Bertrand I
Yacoby, Amir
Date Issued
January 2022
Journal
Nature Physics
Publisher
Springer Science and Business Media LLC
Citation
Pierce, Andrew T, Xie, Yonglong, Lee, Seung Hwan, Forrester, Patrick R, Wei, Di S et al. 2022. "Thermodynamics of free and bound magnons in graphene." Nature Physics, 18 (1).
Version
Final published version
Abstract
AbstractSymmetry-broken electronic phases support neutral collective excitations. For example, monolayer graphene in the quantum Hall regime hosts a nearly ideal ferromagnetic phase at specific filling factors that spontaneously breaks the spin-rotation symmetry1–3. This ferromagnet has been shown to support spin-wave excitations known as magnons that can be electrically generated and detected4,5. Although long-distance magnon propagation has been demonstrated via transport measurements, important thermodynamic properties of such magnon populations—including the magnon chemical potential and density—have not been measured. Here we present local measurements of electron compressibility under the influence of magnons, which reveal a reduction in the gap associated with the ν = 1 quantum Hall state by up to 20%. Combining these measurements with the estimates of temperature, our analysis reveals that the injected magnons bind to electrons and holes to form skyrmions, and it enables the extraction of free magnon density, magnon chemical potential and average skyrmion spin. Our methods provide a means of probing the thermodynamic properties of charge-neutral excitations that are applicable to other symmetry-broken electronic phases.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/s41567-021-01421-x
