Directional Manipulation of a Staggered Charge Density Wave and Kondo Resonance in UTe2

TL;DR

This study reveals a magnetic field-controlled, anisotropic charge density wave and Kondo resonance in UTe2, demonstrating their interplay and providing insights into the material's correlated normal state and potential for tuning electronic orders.

Contribution

It uncovers a directional-dependent charge density wave and its control via magnetic field, highlighting orbital-driven mechanisms and the interplay with Kondo hybridization in UTe2.

Findings

Discovered a staggered charge-density-wave in UTe2.

Demonstrated magnetic field suppression of the CDW along a specific crystallographic direction.

Observed concomitant suppression and evolution of the Kondo resonance with field orientation.

Abstract

UTe2 is a rare example of a correlated quantum material in which unconventional density wave orders, Kondo physics, spin-triplet pairing, and reentrant superconductivity coexist within the same electronic system. Its superconducting state develops out of a strongly correlated normal phase. The identification and control of competing or intertwined normal-state orders are thus central to elucidating the electronic landscape from which its superconductivity arises. Here, using scanning tunnelling microscopy (STM) in a vector magnetic field, we uncover a previously unreported staggered charge-density-wave (CDW) in high-quality UTe2 crystals and demonstrate its strong directional response to an external magnetic field: the staggered CDW is completely quenched by a modest 1.7 T field aligned with the quasi-one-dimensional uranium chain direction (a-axis), while remaining robust against fields along other crystallographic directions. This pronounced anisotropy is consistent with an orbital-driven mechanism that leads to a field-tuned quantum phase transition. Strikingly and counterintuitively, the same field orientation and strength concomitantly alter the hybridization gap and suppress the 5f Kondo resonance. Modelling indicates that this correlated evolution arises from a switch of the dominant hybridization channel from Te 5p- U 5f to U 6d- U 5f coupling, suggesting an intimate interplay between CDW and the Kondo effect. Our work establishes an effective tuning knob for the intertwined orders in UTe2 and provides evidence for orbital-selective Kondo hybridization, shedding light on its correlated normal state.