Quantum Leap in Graphite: Attoscience Lights the Way to Superconductivity
Advancements in attosecond soft-X-ray spectroscopy by ICFO researchers have transformed material analysis, particularly in studying light-matter interactions and many-body dynamics, with promising implications for future technological applications.
Breakthrough in Attosecond Soft-X-ray Spectroscopy
X-ray absorption spectroscopy, an essential tool in material analysis, has evolved with the advent of attosecond soft-X-ray pulses. These pulses allow simultaneous analysis of a material's entire electronic structure, a breakthrough led by the ICFO team. A recent study demonstrated the manipulation of graphite's conductivity through light-matter interaction, revealing potential applications in photonic circuits and optical computing. This advancement in spectroscopy opens new avenues for investigating many-body dynamics in materials, a key challenge in modern physics.
Attosecond soft-X-ray pulses with a duration between 23 as and 165 as and concomitant coherent soft-X-ray bandwidth from 120 to 600 eV allow interrogation of the entire electronic structure of a material at once. The combination of time resolution to detect electronic motion in real-time and the coherent bandwidth that registers where the change happens provides an entirely new and powerful tool for solid-state physics and chemistry.
Exposing graphite to an intense ultrashort mid-infrared laser pulse induces a highly conductive light-matter hybrid phase as optically excited electrons strongly couple to coherent optical phonons. The observations of such a strongly optically driven many-body state becomes possible by studying the lifetime of the excited electronic states with an attosecond soft-X-ray pulse.
Recent Study by ICFO Researchers
In a recent study published in the journal Nature Communications, ICFO researchers observed a light-induced increase and control of the conductivity in graphite by manipulating the many-body state of the material. The researchers used innovative measurement techniques, including carrier-envelope-phase-stable sub-2-cycle optical pulses and attosecond soft-X-ray absorption measurement, to probe the electronic dynamics of graphite.
By optically exciting the material with a powerful light pulse, the researchers were able to observe how the electrons relax within the graphite, individually and as a whole system. This observation revealed an increase in the material's optical conductivity, showing signatures of a superconductivity phase.
The results of this study have promising implications for the field of photonic integrated circuits and optical computing, where light can be used to manipulate electrons and control material properties. This breakthrough in attosecond soft-X-ray spectroscopy provides a new realm of physics for investigating and manipulating correlated phases of matter in real-time, which is essential for modern technologies.
Electron Dynamics in Graphite
Unlike other methods of manipulating material properties, such as twistronics and twisted bilayer graphene, the ICFO researchers optically excite the graphite by using a powerful light pulse. This excites the electrons into high energy states, allowing the researchers to observe how they relax within the material and interact with the lattice.
The researchers utilized coherent phonons, collective excitations of atoms within the graphite, to observe the behavior of the electrons. These coherent phonons efficiently transport energy within the material, and the electrons seem to ride these waves, generating artificial superconductivity signatures.
The observation of electron dynamics in graphite provides insights into the manipulation of material properties using light. It offers new possibilities for controlling and manipulating material function, which has significant implications for future technological advancements.
