Lattice Effects on Nematic Quantum Criticality in Metals

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Critical Phenomena

Background:

• Metals near a nematic quantum critical point are theoretically predicted to exhibit non-Fermi-liquid behavior due to incoherent electronic excitations.
• Existing theories often neglect the coupling between electronic nematicity and lattice strain.

Purpose of the Study:

• To investigate the impact of electron-lattice coupling on electronic excitations near nematic quantum critical points.
• To re-evaluate the theoretical predictions of non-Fermi-liquid behavior in such systems.

Main Methods:

• Theoretical modeling incorporating a symmetry-allowed coupling between the electronic nematic variable and crystalline lattice strain.
• Analysis of critical fluctuations and their interaction with noncritical lattice shear modes.

Main Results:

• The coupling to lattice strain significantly modifies critical fluctuations, largely cutting them off.
• Thermodynamics at low temperatures are predicted to remain Fermi-liquid type.
• Depending on Fermi surface geometry, either the entire Fermi surface remains cold or only specific hot spots emerge.

Conclusions:

• The inclusion of electron-lattice coupling challenges the prevailing theory of widespread non-Fermi-liquid behavior near nematic quantum critical points.
• The findings suggest that Fermi-liquid behavior is more robust, with potential implications for understanding iron-based superconductors.