Related papers: Mesoscopic structural phase progression in photo-e…
The configuration and evolution of coexisting mesoscopic domains with contrasting material properties are critical in creating novel functionality through emergent physical properties. However, current approaches that map the domain…
Oxides exhibiting insulator-metal transitions are promising candidates for next generation ultrafast electronic switching devices. However, critical gaps remain in understanding the onset of strain and its dynamics as these materials…
Vanadium dioxide (VO2) exhibits an insulator-to-metal transition accompanied by a structural transition near room temperature. This transition can be triggered by an ultrafast laser pulse. Exotic transient states, such as a metallic state…
The structural and electronic recovery pathways of a photoexcited ultrathin VO2 film at nanosecond time scales have been studied using time-resolved x-ray diffraction and transient optical absorption techniques. The recovery pathways from…
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…
Concurrent structural and electronic transformations in VO2 thin films are of twofold importance: enabling fine-tuning of the emergent electrical properties in functional devices, yet creating an intricate interfacial domain structure of…
Upon intense femtosecond photo-excitation, a many-body system can undergo a phase transition through a non-equilibrium route, but understanding these pathways remains an outstanding challenge. Here, we use time-resolved second harmonic…
Using light to control transient phases in quantum materials is an emerging route to engineer new properties and functionality, with both thermal and non-thermal phases observed out of equilibrium. Transient phases are expected to be…
The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one of the longest-standing problems in condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether the transition is primarily…
Strongly correlated materials that exhibit an insulator-metal transition are key candidates in the search for new computing platforms. Understanding the pathways and timescales underlying the electrically-driven insulator-metal transition…
We have systematically studied a variety of vanadium dioxide (VO2) crystalline forms, including bulk single crystals and oriented thin films, using infrared (IR) near-field spectroscopic imaging techniques. By measuring the IR spectroscopic…
The high-pressure behavior of monoclinic VO$_2$ is revisited by a combination of Raman spectroscopy and X-ray diffraction on a single crystal under hydrostatic conditions at room temperature. A soft mode is observed up to P$_c$ = 13.9(1)…
Vanadium dioxide with metal-to-insulator transition (MIT) that is triggered by heat, current or light is a promising material for modern active THz/mid-IR metasurfaces and all-optical big data processing systems. Multilayer VO2-based active…
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…
We apply ultrafast spectroscopy to establish a time-domain hierarchy between structural and electronic effects in a strongly-correlated electron system. We discuss the case of the model system VO2, a prototypical non-magnetic compound that…
The ultrafast photoinduced insulator-metal transition in VO2 is studied at different temperatures and excitation fluences using multi-THz probe pulses. The spectrally resolved mid-infrared response allows us to trace separately the dynamics…
Selective optical excitation of a substrate lattice can drive phase changes across hetero-interfaces. This phenomenon is a non-equilibrium analogue of static strain control in heterostructures and may lead to new applications in optically…
Metastable self-organized electronic states in quantum materials are of fundamental importance, displaying emergent dynamical properties that may be used in new generations of sensors and memory devices. Such states are typically formed…
We have developed a new optical microscopy technique able to track micron-sized surface clusters as temperature is varied. Potential candidates for study include phase separated metal-insulator materials, ferroelectrics, and porous…
A deep understanding of molecular photo-transformations is challenging because of the complex interaction between the configurations of electrons and nuclei. An initial optical excitation dissipates energy into electronic and structural…