Superconducting nonlinear transport in optically driven high-temperature K₃C₆₀.

Area of Science:

• Condensed matter physics
• Quantum materials science
• Optoelectronics

Background:

• Optically driven quantum materials display non-equilibrium phenomena.
• Transient electrical responses are crucial for material functionality but are difficult to measure at high temporal resolution.
• Characterizing current-voltage (I-V) nonlinearities below 1 THz is challenging.

Purpose of the Study:

• To investigate the transient electrical transport properties of photo-excited K3C60.
• To explore the linear and nonlinear current-voltage characteristics at picosecond timescales.
• To understand the nature of light-induced superconducting states in K3C60.

Main Methods:

• Ultrafast transport measurements on thin films of K3C60.
• Integration of K3C60 films with photo-conductive switches and co-planar waveguides.
• Measurement of current-voltage (I-V) responses below 1 THz with picosecond temporal resolution.

Main Results:

• Observed characteristic nonlinear current-voltage responses in photo-excited K3C60 films.
• Evidence for photo-induced granular superconductivity in the material.
• New insights into the light-induced superconducting-like state above the equilibrium critical temperature (Tc).

Conclusions:

• Ultrafast transport measurements provide valuable data on non-equilibrium states in quantum materials.
• Photo-induced superconductivity in K3C60 offers potential for integration into high-speed optoelectronic devices.
• The findings advance the understanding of light-matter interactions in quantum materials.