German researchers at the Max Planck Institute for the Structure and Dynamics of Matter have made a significant discovery in the field of quantum materials. By using tailored laser drives, they found a more efficient method for creating a previously observed metastable, superconducting-like state in a fullerene-based material (K3C60) using laser light.
The team was 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 their interest in this nonlinear response is driven by how molecular or phonon modes in solids can be driven to large amplitudes. This has led to an amplification of electronic properties like superconductivity.
The findings provide more insight into the microscopic mechanism of photo-induced superconductivity, according to Edward Rowe, a Ph.D. student working with Cavalleri. He notes that identifying the resonance frequency will allow theoreticalists to understand which excitations are important in this effect.
Rowe also suggests 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 it returns to its non-superconducting equilibrium state, potentially allowing it to be sustained continuously.
Overall, this discovery has significant implications for our understanding of quantum materials and their potential applications in fields such as electronics and energy conversion.