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Abstract Overdoped cuprate superconductors are strange metals above their superconducting transition temperature. In such materials, the electrical resistivity has a strong linear dependence on temperature (T) and electrical current is not carried by electron quasiparticles as in conventional metals. Here we demonstrate that the strange metal behaviour co-exists with strongly temperature-dependent critical spin fluctuations showing dynamical scaling across the cuprate phase diagram. Our neutron scattering observations and the strange metal behaviour are consistent with a spin density wave quantum phase transition in a metal with spatial disorder in the tuning parameter. Numerical computations using a theory of spin density waves in a disordered metal yield an extended ‘Griffiths phase’ with scaling properties in agreement with experimental observations. Thus we establish that low-energy spin excitations and spatial disorder are central to the strange metal behaviour.
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This content will become publicly available on February 1, 2027
Extended strange metal regime from superconducting puddles
We study a model of mesoscale superconducting puddles in a metal, represented as dynamical impurities interacting with a finite number of electronic channels via Andreev and normal scattering. We identify conditions under which the collection of puddles make a T-linear contribution to the resistivity and a T ln(1/T ) to the specific heat and thermopower. This behavior emerges in an intermediate temperature range that extends from an upper energy scale set by the renormalized charging energy of the puddles, and down to an exponentially small scale associated with a charge-Kondo crossover, provided that the number of electronic channels interacting with the puddle is large. The phenomenology of our model resembles the apparent extended strange metal regime observed in overdoped cuprates which exhibits T-linear resistivity at low T over a finite range of doping. We also propose to engineer a strange metal from suitably designed superconducting grains in a metallic matrix.
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- Award ID(s):
- 2310312
- PAR ID:
- 10676490
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Physical Review B
- Volume:
- 113
- Issue:
- 7
- ISSN:
- 2469-9950
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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