Pair-Density-Wave Superconductivity: A Microscopic Model on the 2D Honeycomb Lattice

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Superconductivity

Background:

• Pair-density wave (PDW) is an exotic superconducting state with oscillating order, rarely observed in 2D systems.
• Establishing microscopic models with long-range PDW order in the ground state remains a significant challenge.

Purpose of the Study:

• To investigate pair-density wave (PDW) superconductivity in a minimal model of spinless fermions.
• To explore PDW ordering in a 2D honeycomb lattice model with specific interactions.

Main Methods:

• Utilized state-of-the-art density-matrix renormalization group (DMRG) studies.
• Analyzed a t-V1-V2 model of spinless fermions on six-leg and eight-leg honeycomb cylinders at finite doping.

Main Results:

• Demonstrated the emergence of pair-density wave (PDW) ordering in the ground state.
• Observed quasi-long-range order with a divergent PDW susceptibility.
• Confirmed the persistence of the PDW state on wider cylinders with 2D-like Fermi surfaces.

Conclusions:

• Presented the first controlled numerical evidence of pair-density wave (PDW) in systems exhibiting 2D-like Fermi surfaces.
• The proposed minimal model provides a platform for studying exotic PDW superconductivity.