Deconstructing magnetization noise: Degeneracies, phases, and mobile fractionalized excitations in tetris artificial spin ice

Journal Article · Wed Oct 18 00:00:00 UTC 2023 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.2310777120 · OSTI ID:2202870

Goryca, Mateusz  ^[1]; Zhang, Xiaoyu ^[2]; Ramberger, Justin ^[3]; Watts, Justin D. ^[4]; Nisoli, Cristiano  ^[5]; Leighton, Chris  ^[3]; Schiffer, Peter  ^[6]; Crooker, Scott A. ^[7]

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1. 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
2. Department of Applied Physics, Yale University, New Haven, CT 06520
3. Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455
4. Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455
5. Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545
6. Department of Applied Physics, Yale University, New Haven, CT 06520, Department of Physics, Yale University, New Haven, CT 06520
7. National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, NM 87545

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.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Science Foundation (NSF); Norwegian Financial Mechanism; Polish National Agency for Academic Exchange; USDOE; USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: 89233218CNA000001; SC0020162
• OSTI ID: 2202870
• Report Number(s): LA-UR--23-30254; e2310777120
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 43 Vol. 120; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English