Theory of Kondo hybridization wave in Kondo lattice

Abstract

Recent scanning tunneling microscopy experiments have discovered emergent spatially modulated Kondo hybridization wave (KHW) order in the heavy fermion superconductor UTe$_2$ and the artificial Kondo lattice system 1T/1H-TaS$_2$, challenging the conventional paradigm of spatially uniform Kondo hybridization in heavy fermion physics. Here, we develop a microscopic theory for KHW order based on the canonical square-lattice Kondo lattice model within the large-$N$ fermionic mean-field approximation. We systematically identify stable modulated KHW phases and establish their ground-state phase diagram. The prominent $\boldsymbol{Q}=(0,π)$ KHW phase yields uniaxial stripe modulation of the Kondo hybridization gap, which faithfully reproduces the spatial modulation pattern observed in UTe$_2$. Moreover, its inherent unit-cell-doubling modulation precisely accounts for the spectroscopic features measured in 1T/1H-TaS$_2$. We further predict a characteristic in-plane conductivity anisotropy that serves as a definitive transport fingerprint to discriminate KHW states with distinct ordering wavevectors. Our work provides a microscopic foundation for the newly observed KHW order and establishes a unified theoretical framework for understanding emergent modulated hybridization phenomena in heavy fermion materials.