The emergence of ultrafast laser technology and the capability of producing ultra-short light pulses has enabled access to light-matter interaction at very short timescales. Furthermore, ultra-short high-power laser pulses can induce strong perturbations in electronic and crystallographic structures and drive materials into unusual phases and new out-of-equilibrium states.

The advances in the generation and detection of ultra-short pulses has pushed the boundaries of time-resolved techniques forward, so as to probe the ultrafast dynamics in condensed matter on the picosecond-, femtosecond-, and down to the attosecond timescales for wavelengths across the electromagnetic spectrum, ranging from the terahertz region to x-rays. Ultrafast techniques have the flexibility of different combinations of excitation and probe sources. These allow specific interactions to be studied. For instance, one has optical pump - XUV probe measurements of element-specific ultrafast magnetic and electronic dynamics, transient absorption spectroscopy of strongly correlated electron materials in the XUV regime, or intense ultrafast laser pulses in the THz-range inducing nonlinear phononic interactions detected by an optical probe.

Additionally, it is important to develop theoretical methods to simulate high peak power laser-matter interactions in the pulsed regime, and to predict the evolution of far-from-equilibrium systems.

These ultrafast processes can be exploited for applications, from sensing to data storage, and have provided great knowledge of non-equilibrium electronic, optical, structural and magnetic states and phase transitions in matter.

The aim of this mini-colloquium is to present and discuss recent experimental and theoretical developments, exploring ideas and current knowledge and broadening the scope of future research towards advanced technologies based on non-equilibrium ultrafast phenomena. The mini-colloquium will address (as a list of possible topics):

1. Ultrafast magnetic and electronic dynamics
2. Light-induced phase transitions: (superconductivity, magnetism and ferroelectricity)
3. Light-wave coherent control of quantum systems
4. Experimental challenges: tabletop laser sources (THz, XUV, …), laser pulse characterization, time-resolved spectroscopy techniques.
5. Theory of time-dependent ultrafast and non-equilibrium processes at femto- and attosecond time scales.