Itinerant quantum critical point with fermion pockets and hotspots

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Strongly Correlated Electron Systems

Background:

• Metallic quantum criticality is a key area in condensed matter physics.
• Understanding correlated electronic systems requires reconciling analytical and numerical results.
• High-Tc cuprates and critical metals exhibit Fermi surface and antiferromagnetic fluctuations relevant to non-Fermi liquid behavior.

Purpose of the Study:

• To investigate the itinerant quantum critical point on a 2D square lattice with antiferromagnetic spin fluctuations.
• To simulate a system resembling the Fermi surface setup and low-energy antiferromagnetic fluctuations in high-Tc cuprates.
• To precisely reveal quantum critical scaling behaviors and understand non-Fermi liquid phenomena.

Main Methods:

• Development of a state-of-the-art large-scale quantum Monte Carlo simulation technique.
• Systematic investigation of a 2D square lattice with antiferromagnetic spin fluctuations.
• Accessing large system sizes ([Formula: see text]) for high-precision analysis.

Main Results:

• Antiferromagnetic spin fluctuations induce effective interactions among fermions.
• Fermions modify the bosonic critical point to a new universality class, distinct from Ising and Hertz-Mills-Moriya RPA predictions.
• A finite anomalous dimension ([Formula: see text]) in the bosonic propagator and non-Fermi liquid behavior in fermions at hotspots were observed.
• Fermion pockets and energy gap opening at hotspots were identified in the antiferromagnetically ordered metallic phase.

Conclusions:

• The study provides a precise understanding of quantum critical scaling behaviors in 2D metals.
• Results bridge theoretical and numerical advancements in metallic quantum criticality.
• Findings offer insights into the non-Fermi liquid behaviors observed in materials like high-Tc cuprates.