Mottness collapse and T-linear resistivity in cuprate superconductors.

Area of Science:

• Condensed matter physics
• Materials science

Background:

• Cuprate superconductors exhibit a pseudogap phase that collapses at a critical point, leading to a strange metal phase.
• The strange metal phase is characterized by resistivity linearly dependent on temperature (T-linear resistivity).
• Existing theories face challenges in explaining T-linear resistivity, often requiring additional length scales or non-fermionic degrees of freedom.

Purpose of the Study:

• To investigate the underlying physics of the strange metal phase in cuprate superconductors.
• To reconcile the requirements of quantum criticality theories with the observed properties of strange metals.
• To explore the role of dynamical spectral weight transfer in the Hubbard model.

Main Methods:

• Development of a low-energy theory for the Hubbard model.
• Incorporation of dynamical spectral weight transfer into the theoretical framework.
• Analysis of the behavior of extra degrees of freedom under varying doping and temperature.

Main Results:

• The low-energy theory successfully incorporates the necessary extra degrees of freedom.
• Dynamical spectral weight transfer leads to degrees of freedom that either decouple at critical doping (Mottness collapse) or unbind at critical temperature.
• These phenomena explain the emergence of the strange metal behavior and T-linear resistivity.

Conclusions:

• The proposed theory provides a unified explanation for Mottness collapse and strange metal behavior.
• Dynamical spectral weight transfer is identified as a key mechanism driving these emergent phenomena.
• The findings offer a new perspective on the complex physics of high-temperature superconductors.