Vertex corrections near the stripe phase

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• High-temperature cuprate superconductors exhibit complex electronic phases near optimal doping.
• Stripe instabilities, involving spatially modulated charge and spin density, are crucial for understanding their behavior.
• Fermion quasiparticles interacting with charge and spin fluctuations are key to these phenomena.

Purpose of the Study:

• To calculate vertex corrections in a model of fermion quasiparticles coupled to charge and spin fluctuations.
• To investigate the impact of incommensurate stripe phases on scattering mechanisms near instabilities.
• To determine the behavior of vertex corrections in the context of high-Tc cuprates.

Main Methods:

• Utilized a model for fermion quasiparticles interacting with charge and spin fluctuations.
• Calculated vertex corrections, considering the effects of stripe instabilities.
• Analyzed the implications of incommensuration, as observed via neutron scattering, on the model's structure.

Main Results:

• The logarithmic divergence of the vertex, typical of antiferromagnetic instabilities, is absent in the stripe phase due to incommensuration.
• The vertex corrections are found to be negative in the relevant kinematic regime.
• This negativity effectively reduces the interaction strength between quasiparticles.

Conclusions:

• The incommensuration of charge and spin modulation in stripe phases simplifies the theoretical treatment of vertex corrections.
• The reduced effective interaction strength has significant implications for understanding transport and other properties in cuprates.
• The findings are applicable to a broader range of generic incommensurate electronic instabilities.