Pressure-enhanced f-electron orbital weighting in UTe₂ mapped by quantum interferometry

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Uranium ditelluride (UTe2) exhibits complex superconducting phases under pressure and magnetic fields.
• Previous studies revealed a quasi-2D Fermi surface at ambient pressure, but its pressure evolution was unknown.

Purpose of the Study:

• To investigate the pressure-dependence of the UTe2 Fermi surface up to 19.5 kbar.
• To understand how the electronic structure changes with pressure, particularly concerning superconductivity.

Main Methods:

• Quantum interference oscillations were measured under applied pressure.
• A magnetic field was used to suppress superconductivity and antiferromagnetism.
• A tight-binding model was computed to interpret the results.

Main Results:

• The quasi-2D Fermi surface remains largely unchanged up to 19.5 kbar, with no reconstruction observed.
• Oscillatory frequencies increased with pressure, indicating enhanced warping of Fermi sheets.
• This warping correlates with an increased f-orbital contribution at the Fermi level.

Conclusions:

• The Fermi surface of UTe2 is robust against pressure changes up to 19.5 kbar.
• High-pressure quantum interference measurements are effective for probing electronic structures in heavy fermion systems.
• The study provides insights into the electronic behavior of UTe2 near its superconducting critical pressure.