Goryca Mateusz, Zhang Xiaoyu, Ramberger Justin, Watts Justin D, Nisoli Cristiano, Leighton Chris, Schiffer Peter, Crooker Scott A
National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, NM 87545.
Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland.
Proc Natl Acad Sci U S A. 2023 Oct 24;120(43):e2310777120. doi: 10.1073/pnas.2310777120. Epub 2023 Oct 18.
Direct detection of spontaneous spin fluctuations, or "magnetization noise," is emerging as a powerful means of revealing and studying magnetic excitations in both natural and artificial frustrated magnets. Depending on the lattice and nature of the frustration, these excitations can often be described as fractionalized quasiparticles possessing an effective magnetic charge. Here, by combining ultrasensitive optical detection of thermodynamic magnetization noise with Monte Carlo simulations, we reveal emergent regimes of magnetic excitations in artificial "tetris ice." A marked increase of the intrinsic noise at certain applied magnetic fields heralds the spontaneous proliferation of fractionalized excitations, which can diffuse independently, without cost in energy, along specific quasi-1D spin chains in the tetris ice lattice.
直接探测自发自旋涨落，即“磁化噪声”，正成为揭示和研究天然及人工受挫磁体中磁激发的一种强大手段。根据晶格结构和受挫性质，这些激发通常可描述为具有有效磁荷的分数化准粒子。在此，通过将热力学磁化噪声的超灵敏光学探测与蒙特卡罗模拟相结合，我们揭示了人工“俄罗斯方块冰”中磁激发的涌现态。在某些外加磁场下，本征噪声的显著增加预示着分数化激发的自发增殖，这些激发能够沿着俄罗斯方块冰晶格中的特定准一维自旋链独立扩散，且无需能量消耗。
