Kinetic Blockade and Filamentary Pair Density Waves in Strain-Engineered Graphene

TL;DR

This paper reveals a novel strain-induced filamentary superconducting state in graphene, driven by geometric effects rather than density of states, characterized by a pair density wave with sign-reversing order parameter.

Contribution

It introduces the concept of a kinetic blockade and demonstrates filamentary pair density waves as a new form of superconductivity in strain-engineered graphene.

Findings

Superconductivity appears as filaments at geometric nodes.

Strain causes sublattice polarization, inhibiting flat band pairing.

Sign-reversing order parameter detectable via impurity modes.

Abstract

We investigate superconductivity in strain-engineered graphene using a self-consistent Bogoliubov-de Gennes approach. Challenging the paradigm that the high density of states in flat bands universally enhances pairing, we identify a "kinetic blockade" mechanism: strain-induced sublattice polarization segregates electronic states, rendering these singularities inert. Instead, superconductivity emerges as robust filaments at geometric nodes, forming a pair density wave. This state features a sign-reversing order parameter, detectable via impurity-induced zero-energy modes. Our findings reveal a unique geometric origin for filamentary superconductivity, offering new perspectives on strain-tuned quantum phases in Dirac materials.