Our preprint “Light-enhanced electron-phonon coupling from nonlinear electron-phonon coupling” is available on arXiv. In this work, it is shown how one can amplify electron-lattice coupling by using lasers that are tuned to a phonon, that is coupled quadratically to the electrons of the material. Such enhanced electron-lattice coupling can lead to the formation of polarons – electrons coupled to a “cloud” of lattice distortion – or even make the system superconducting. It has recently been debated how possible light-induced superconductivity in carbon football molecular crystal (“fullerenes”) may come about, and nonlinear electron-phonon coupling might play an important role. Similarly, more direct signatures of light-enhanced electron-lattice coupling have been observed in metallic bilayers of the carbon flatland material graphene. Now experiments have to be performed to check the hypothesis of our theory paper.
Our work “Energy Dissipation from a Correlated System Driven Out of Equilibrium” was published in Nature Communications (doi:10.1038/ncomms13761).
In a new theory published on arXiv today we show how a laser beam can exert control in a system with competing superconducting and charge orders. The underlying mechanism with a striking resonance for photon frequencies near the gap edge may even be used to understand light-induced superconductivity. The above figure illustrates how a symmetry between the competing orders allows for low-energy excitations corresponding to a rotation of a composite order parameter towards charge order (CDW, left) or towards superconductivity (SC, right).
This is the new webspace for the Sentef Lab, a DFG funded Emmy Noether Research Group starting in September 2016. More information can be found in the official press release of the MPSD.