Researchers at the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg, Germany, have been delving into the impact of tailored laser drives on manipulating quantum materials away from equilibrium. This work has notably revealed intriguing insights in unconventional superconductors, showcasing enhanced electronic coherences and super-transport in non-equilibrium states.
Yet, due to the complexities of these experiments, systematic study and optimization of these phenomena remain a challenge, hindering practical applications.
In a recent breakthrough, the same research team discovered a significantly more efficient method to induce a previously observed metastable, superconducting-like state in K₃C₆₀ using laser light. The Cavalleri group’s work, published in Nature Physics, hinged on the Institute’s advanced laser technology. By tuning the light source to a lower frequency of 10 THz, previously unattainable, they managed to recreate the long-lasting superconducting-like state in the fullerene-based material with a 100-fold reduction in pulse intensity.
This light-induced state was directly observed to endure at room temperature for 100 picoseconds, with a predicted lifetime of at least 0.5 nanoseconds (a billionth of a second, a picosecond is a trillionth).
Edward Rowe, a Ph.D. student in the Cavalleri group and lead author, believes that a higher repetition rate light source at the 10 THz frequency could extend the metastable state’s duration. This could potentially maintain the superconducting-like state continuously, preventing it from returning to its non-superconducting equilibrium state between pulses.
These experiments illustrate how technological advancements can make previously impractical phenomena applicable. MPSD Director Andrea Cavalleri underscores the importance of laser sources evolving in tandem with these studies to advance the field towards future technologies, marking the culmination of two decades of effort in exploring these effects.
Source: Max Planck Society