Ultrafast Sciences in Quantum Materials

Abstract

Ultrashort laser pulses, with duration in the femto-to-picosecond regime, usher in an era of time-domain study of quantum materials, in which many-body interactions can lead to remarkable properties that are beyond the single-particle description of solids by the band theory. Not only do ultrafast pulses reveal microscopic dynamics and collective excitations with unprecedented temporal resolution, the corresponding high peak field also enables a suite of nonlinear spectroscopies that are otherwise inaccessible. More recently, an intense light pulse has also been shown to induce a variety of nonequilibrium states, from superconductivity to ferroelectricity, whose origins are subject of intense investigations. This chapter offers a review of ultrafast studies in quantum materials, and recent progress is discussed from the perspective of both ultrafast probing and control of condensed matter systems. The review is concluded with a description of advanced femtosecond techniques used in this dissertation and an outlook of next-generation tools.