Critical fluctuations and noise spectra in two-dimensional Fe₃GeTe₂ magnets.

ABSTRACT: Critical fluctuations play a crucial role in determining spin orders in low-dimensional magnetic materials. However, experimentally linking these fluctuations to scaling theory-and thereby uncovering insights into spin interaction models-remains a challenge. Here, we utilize a nitrogen-vacancy center-based quantum decoherence imaging technique to probe critical fluctuations in the van der Waals magnet Fe₃GeTe₂. Our data reveal that critical fluctuations produce a random magnetic field, with noise spectra undergoing significant changes near the critical temperature. To explain this phenomenon, we developed a theoretical framework showing that the spectral density exhibits 1/f noise characteristics near the critical temperature, transitioning to white noise behavior awa

SUBMITTER: Li Y 

PROVIDER: S-EPMC12479839 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature