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Title: Singular charge fluctuations at a magnetic quantum critical point
Strange metal behavior is ubiquitous in correlated materials, ranging from cuprate superconductors to bilayer graphene, and may arise from physics beyond the quantum fluctuations of a Landau order parameter. In quantum-critical heavy-fermion antiferromagnets, such physics may be realized as critical Kondo entanglement of spin and charge and probed with optical conductivity. We present terahertz time-domain transmission spectroscopy on molecular beam epitaxy–grown thin films of YbRh 2 Si 2 , a model strange-metal compound. We observed frequency over temperature scaling of the optical conductivity as a hallmark of beyond-Landau quantum criticality. Our discovery suggests that critical charge fluctuations play a central role in the strange metal behavior, elucidating one of the long-standing mysteries of correlated quantum matter.  more » « less
Award ID(s):
1920740 1720595
Author(s) / Creator(s):
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Date Published:
Journal Name:
Medium: X
Sponsoring Org:
National Science Foundation
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