Absence of bulk charge density wave order in the normal state of UTe₂

A spatially modulated superconducting state at zero magnetic field, known as pair density wave (PDW), is a tantalizing state of matter with unique properties. PDWs have been observed in diverse spin-singlet superconductors ranging from high-temperature cuprate and Fe-based superconductors to kagome and two-dimensional chalcogenide compounds. Recent scanning tunneling microscopy (STM) studies reveal that spin-triplet superconductor UTe₂ hosts an unprecedented spin-triplet PDW whose wavevectors are indistinguishable from a preceding charge-density wave (CDW) order that survives to temperatures well above the superconducting critical temperature, Tc. Whether the PDW is the mother or a subordinate order remains unsettled. Here, based on a systematic search for bulk charge order above Tc using resonant elastic X-ray scattering (REXS), we show that the structure factor of charge order previously identified by STM is absent in the bulk within the sensitivity of REXS, which implies that the reported CDW order in the normal state of UTe₂ is a surface phenomenon. Our results invite two scenarios: either the density-wave orders condense simultaneously at Tc in the bulk, in which case PDW order is likely the mother phase, or these modulations are restricted to the surface.