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S trange-metal behavior has been observed in materials ranging from high-temperature superconductors to heavy fermion metals. In conventional metals, current is carried by quasiparticles; although it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is lacking. We measured shot noise to probe the granularity of the current-carrying excitations in nanowires of the heavy fermion strange metal YbRh2Si2. When compared with conventional metals, shot noise in these nanowires is strongly suppressed. This suppression cannot be attributed to either electron-phonon or electron-electron interactions in a Fermi liquid, which suggests that the current is not carried by well-defined quasiparticles in the strange-metal regime that we probed. Our work sets the stage for similar studies of other strange metals.
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This content will become publicly available on February 1, 2026
Anomalous shot noise in a bad metal β-tantalum
We investigate the electronic shot noise produced by nanowires of β-Ta, an archetypal “bad” metal with resistivity near the Ioffe–Regel localization limit. The Fano factor characterizing the shot noise exhibits a strong dependence on temperature and is suppressed compared to the expectations for quasiparticle diffusion, but hopping transport is ruled out by the analysis of scaling with the nanowire length. These anomalous behaviors closely resemble those of strange metal nanowires, suggesting that β-Ta may host a correlated electron liquid. This material provides an accessible platform for exploring exotic electronic states of matter.
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- Award ID(s):
- 2005786
- PAR ID:
- 10574287
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Applied Physics Letters
- Volume:
- 126
- Issue:
- 8
- ISSN:
- 0003-6951
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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