Researchers at the Max Planck Institute for the Structure and Dynamics of Matter in Germany have made a significant discovery in the field of quantum materials. By using tailored laser drives, the team found a more efficient method for creating a previously observed metastable, superconducting-like state in a fullerene-based material (K3C60) using laser light.
The researchers were able to recreate the long-lived superconducting-like state in the material by tuning the light source to 10 THz, a lower frequency than previously possible, and reducing the pulse intensity by a factor of 100. This allowed them to directly observe the light-induced state at room temperature for 100 picoseconds, with a predicted lifetime of at least 0.5 nanoseconds.
Andrea Cavalleri, the founding director of the Max Planck Institute for the Structure and Dynamics of Matter, explained that the group has been interested in the nonlinear response of materials and how molecular or phonon modes in solids can be driven to large amplitudes. This has led to the amplification of electronic properties like superconductivity.
The findings of the group can provide more insight into the microscopic mechanism of photo-induced superconductivity. Edward Rowe, a Ph.D. student working with Cavalleri, noted that the identification of the resonance frequency will allow theorists to understand which excitations are important in this effect.
Rowe also suggested that a light source with a higher repetition rate at the 10 THz frequency could help sustain the metastable state longer. By delivering new pulses before the sample returns to its non-superconducting equilibrium state, it may be possible to sustain the superconducting-like state continuously.