Spin-Induced Optical Conductivity in the Spin-Liquid Candidate Herbertsmithite
We report a direct measurement of the low-frequency optical conductivity of large-area single-crystal herbertsmithite, a promising spin-liquid candidate material, by means of terahertz time-domain spectroscopy. In the spectral range below 1.4 THz, we observe a contribution to the real part of the in...
Main Authors: | , , , , , , , |
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Other Authors: | |
Format: | Article |
Language: | en_US |
Published: |
American Physical Society
2014
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Online Access: | http://hdl.handle.net/1721.1/84975 https://orcid.org/0000-0002-2257-9944 https://orcid.org/0000-0002-6394-4987 https://orcid.org/0000-0002-7406-5283 https://orcid.org/0000-0002-7022-8313 |
Summary: | We report a direct measurement of the low-frequency optical conductivity of large-area single-crystal herbertsmithite, a promising spin-liquid candidate material, by means of terahertz time-domain spectroscopy. In the spectral range below 1.4 THz, we observe a contribution to the real part of the in-plane conductivity σ[subscript ab](ω) from the spin degree of freedom. This spin-induced conductivity exhibits a power-law dependence on frequency σ[subscript ab](ω) ~ ω[superscript β] with β ≈ 1.4. Our observation is consistent with the theoretically predicted low-frequency conductivity arising from an emergent gauge field of a gapless U(1) Dirac spin liquid. |
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