Enhancement Mechanism of Cooper Pair Inertial Mass: Orbital Angular Momentum—Local Field (L×E) Coupling

Abstract

The Cooper pair inertial mass parameter m^* in Ginzburg-Landau theory, characterizing the collective inertial response of the phase-coherent condensate, exhibits dramatic enhancement in strongly correlated superconducting systems. While previous work has established m^* as distinct from the band effective mass m_band, the microscopic mechanisms underlying its significant enhancement in correlated materials remain incompletely understood.

This work develops a comprehensive theoretical framework identifying the coupling between orbital angular momentum and local electric fields (L×E coupling) as a fundamental mechanism for Cooper pair inertial mass enhancement. In systems lacking inversion symmetry, the interaction between electronic orbital angular momentum and strong local electric fields—generated by charge ordering, polar fluctuations, or interface effects—creates an additional inertial resistance to phase coherence establishment.

We demonstrate that L×E coupling operates through dual pathways: at the single-particle level, it generates flat band features that enhance m_band; at the collective level, it introduces additional scattering for phase fluctuations, manifesting as enhanced m^*. The framework establishes scaling relations connecting microscopic coupling strength to macroscopic m^* enhancement, providing quantitative predictions testable through spectroscopic and transport measurements. Application to heavy-fermion superconductors and interface systems reveals consistent agreement with observed mass enhancement phenomena, offering a unified explanation for anomalous inertial response across diverse correlated superconductors.