Linear-in temperature resistivity from an isotropic Planckian scattering rate

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Conventional metals exhibit quadratic temperature-dependent resistivity.
• Strange metals display resistivity linear with temperature, suggesting a fundamental scattering limit.
• The origins of this Planckian limit in strange metals remain largely unknown.

Purpose of the Study:

• Investigate the origins of linear-in-temperature resistivity in strange metals.
• Measure the scattering rate and its properties in a specific cuprate material.
• Determine if the scattering rate saturates at the Planckian limit and its directional dependence.

Main Methods:

• Angle-dependent magnetoresistance measurements on La1.6-xNdx0.4SrxCuO4.
• Quantitative comparison with angle-resolved photoemission spectroscopy data.
• Analysis of charge carrier scattering rates.

Main Results:

• Confirmed a well-defined Fermi surface in the cuprate.
• Observed a linear-in-temperature scattering rate saturating at the Planckian limit (α = 1.2 ± 0.4).
• Found the Planckian scattering rate to be isotropic, contradicting hotspot models.

Conclusions:

• Linear-in-temperature resistivity in strange metals arises from isotropic, momentum-independent inelastic scattering.
• The scattering rate reaches the fundamental Planckian limit.
• Findings challenge existing theoretical models like hotspot models.