相关论文: Investigation of the Non-equilibrium State of Stro…
Metastable phases present a promising route to expand the functionality of complex materials. Of particular interest are light-induced metastable phases that are inaccessible under equilibrium conditions, as they often host new, emergent…
Ultrafast light-matter interaction has emerged as a new mechanism to exert control over the macroscopic properties of quantum materials toward novel functionality. To date, technological applications of these non-thermal phases are limited…
Engineering novel states of matter with light is at the forefront of materials research. An intensely studied direction is to realize broken-symmetry phases that are "hidden" under equilibrium conditions but can be unleashed by an…
Quantum materials represent one of the most promising frontiers in the quest for faster, lightweight, energy efficient technologies. However, their inherent complexity and rich phase landscape make them challenging to understand or…
Optical pulses are routinely used to drive dynamical changes in the properties of solids. In quantum materials, many new phenomena have been discovered, including ultrafast transitions between electronic phases, switching of ferroic orders…
Complex systems are characterized by strong coupling between different microscopic degrees of freedom. Photoexcitation of such materials can drive them into new transient and long-lived hidden phases that may not have any counterparts in…
Controlling quantum materials with ultrafast light pulses enables access to transient and metastable states that are inaccessible under equilibrium conditions. Yet their local dynamics remain poorly understood due to the challenge of…
We study the non-equilibrium structural dynamics of the incommensurate and nearly-commensurate charge-density wave phases in 1T-TaS$_2$. Employing ultrafast low-energy electron diffraction (ULEED) with 1 ps temporal resolution, we…
Ultrafast spectroscopy is an emerging technique with great promise in the study of quantum materials, as it makes it possible to track similarities and correlations that are not evident near equilibrium. Thus far, however, the way in which…
The complex Fermi surfaces of transition-metal dichalcogenides (TMDCs) challenge the standard Peierls-instability-driven charge-density-wave (CDW) formation. Recently, evidence has been accumulating of a prominent role of ionic thermal…
The dynamics of the photoinduced commensurate to incommensurate charge density wave (CDW) phase transition in 4Hb-TaSe2 are investigated by femtosecond electron diffraction. In the perturbative regime the CDW reforms on a 150 ps timescale,…
When electrons in a solid are excited with light, they can alter the free energy landscape and access phases of matter that are beyond reach in thermal equilibrium. This accessibility becomes of vast importance in the presence of phase…
A central paradigm of non-equilibrium physics concerns the dynamics of heterogeneity and disorder, impacting processes ranging from the behavior of glasses to the emergent functionality of active matter. Understanding these complex…
Charge density waves (CDWs) underpin the electronic properties of many complex materials. Near-equilibrium CDW order is linearly coupled to a periodic, atomic-structural distortion, and the dynamics is understood in terms of amplitude and…
Time-resolved dynamics in charge-density-wave materials have revealed interesting out-of-equilibrium electronic responses. However these are typically only performed in a single material possessing a CDW. As such, it is challenging to…
The electronic and structural properties of a material are strongly determined by its symmetry. Changing the symmetry via a photoinduced phase transition offers new ways to manipulate material properties on ultrafast timescales. However, in…
Understanding collective electronic states such as superconductivity and charge density waves is pivotal for fundamental science and applications. The layered transition metal dichalcogenide 1T-TiSe2 hosts a unique charge density wave (CDW)…
Condensed matter physics has been driven forward by significant experimental and theoretical progress in the study and understanding of equilibrium phase transitions based on symmetry and topology. However, nonequilibrium phase transitions…
Symmetry breaking and the emergence of order is one of the most fascinating phenomena in condensed matter physics. It leads to a plethora of intriguing ground states found in antiferromagnets, Mott insulators, superconductors, and…
The complex phase diagram of 1T-TiSe2 consists of a charge density wave (CDW) below 200 K, and CDW fluctuations of still unknown origin at higher temperatures. Here, we use time-resolved extreme ultraviolet momentum microscopy and density…