Phase-resolved Higgs response in superconducting cuprates.

Area of Science:

• High-energy physics
• Condensed matter physics
• Superconductivity

Background:

• The Higgs field imparts mass to elementary particles by coupling to gauge bosons and fermions.
• In superconductors, Cooper pairs exhibit properties analogous to the Higgs field.
• Dissipation channels for the Higgs amplitude mode in superconductors can provide insights into microscopic pairing mechanisms.

Purpose of the Study:

• To investigate the Higgs (amplitude) mode in cuprate thin films.
• To explore the coupling of the Higgs mode to other collective modes.
• To determine if a nonzero pairing amplitude exists above the critical temperature (Tc).

Main Methods:

• Utilized phase-resolved terahertz third harmonic generation (THG).
• Analyzed the Higgs (amplitude) mode in several cuprate thin films.
• Measured THG signals above Tc.

Main Results:

• Observed a heavily damped Higgs mode.
• Detected a universal phase jump in the driven Higgs oscillation.
• Measured a non-vanishing THG signal above Tc.

Conclusions:

• The Higgs mode in cuprates couples to other collective modes.
• The results suggest a potential nonzero pairing amplitude above Tc.
• This research offers new avenues for understanding pairing mechanisms in superconductors.