Magnetic-field-sensitive charge density waves in the superconductor UTe₂

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Superconductivity

Background:

• Triplet superconductivity theoretically predicts exotic excitations like Majorana modes.
• Strongly correlated systems can host novel emergent states when superconductivity is present.

Purpose of the Study:

• To investigate the nature of charge-density-wave (CDW) order in the heavy-fermion triplet superconductor UTe2.
• To understand the relationship between CDW order and superconductivity in UTe2 under magnetic fields.

Main Methods:

• Scanning tunnelling microscopy (STM) was used to map the CDW order.
• A Ginzburg-Landau theory was developed to model the coexistence of superconductivity and CDW states.

Main Results:

• An unusual, multi-component incommensurate CDW order was observed in UTe2.
• The CDW intensity decreased with increasing magnetic field, vanishing at the superconducting critical field (Hc2).
• A theoretical model successfully explained the field-sensitive nature of the CDW originating from pair-density-wave states.

Conclusions:

• A novel magnetic-field-sensitive CDW state coexists with triplet superconductivity in UTe2.
• This discovery provides crucial information for understanding the complex order parameters in UTe2.
• The findings contribute to the broader understanding of exotic states in strongly correlated superconductors.