Related papers: Universal phase dynamics in VO2 switches revealed …
VO2 is a much-discussed material for oxide electronics and neuromorphic computing applications. Here, heteroepitaxy of vanadium dioxide (VO2) was realized on top of oxide nanosheets that cover either the amorphous silicon dioxide surfaces…
Amorphous vanadium dioxide (VO$_{2}$) films deposited by atomic layer deposition (ALD) were crystallized with an ex situ anneal at 660-670 ${\deg}$C for 1-2 hours under a low oxygen pressure (10$^{-4}$ to 10$^{-5}$ Torr). Under these…
The switching and optical properties of phase-change thin films are actively investigated for future smart optical devices. The possibility of having more than one stable state, the large optical contrast between phases, and the fast and…
We present a theoretical investigation of the electronic structure of rutile (metallic) and M$_1$ and M$_2$ monoclinic (insulating) phases of VO$_2$ employing a fully self-consistent combination of density functional theory and embedded…
We report the lattice dynamics of transition metal thin films by using the ultrafast electron diffraction. We observe a suppression of the diffraction intensity in a few picosecond after the photoexcitation, which is directly interpreted as…
Vanadium dioxide (VO$_2$) has received significant interest in the context of nanophotonic metamaterials and memories owing to its reversible insulator-metal transition associated with significant changes in its optical and electronic…
Vanadium dioxide is a complex oxide material, which shows large resistivity and optical reflectance change while transitioning from the insulator to metal phase at ~68 {\deg}C. In this work, we use a modified atmospheric thermal oxidation…
This paper presents a VO2-based metamaterial absorber optimized for ultra-broadband, polarization-insensitive performance in the terahertz (THz) frequency range. The absorber consists of a patterned VO2 metasurface, a low-loss MF2…
We propose experimentally feasible ways to probe universal features of absorbing phase transitions from two different approaches, both based on numerical validations. On one hand, we numerically study a probability distribution of…
We present the first comprehensive broadband optical spectroscopy data on two insulating phases of vanadium dioxide (VO2): monoclinic M2 and triclinic. The main result of our work is that the energy gap and the electronic structure are…
Controlling the insulator-metal transition (IMT) in correlated oxide system through oxygen vacancy ordering opens up a new paradigm for exploring exotic structural transformation and physical functionality. Oxygen vacancy serves as a…
Infrared spectroscopy has emerged as a premier experimental technique to probe enigmatic effects arising from strong correlations in solids. Here we report on recent advances in this area focusing on common patterns in correlated electron…
We introduce ultrafast low-energy electron diffraction (ULEED) in backscattering for the study of structural dynamics at surfaces. Using a tip-based source of ultrashort electron pulses, we investigate the optically-driven transition…
In order to probe the mechanism of solid-solid phase transformations, we have applied ultrafast shock wave compression (120 picosecond duration) and ultrashort (130 femtosecond) x-ray diffraction at the Linac Coherent Light Source (LCLS) to…
Transition metal oxides such as vanadium dioxide (VO$_2$), niobium dioxide (NbO$_2$), and titanium sesquioxide (Ti$_2$O$_3$) are known to undergo a temperature-dependent metal-insulator transition (MIT) in conjunction with a structural…
Phase transitions are key in determining and controlling the quantum properties of correlated materials. Here, by using the powerful combination of precise material synthesis and angle resolved photoelectron spectroscopy, we show evidence…
Transition-metal-dichalcogenides own a variety of structures as well as electronic properties which can be modulated by structural variations, element substitutions, ion or molecule intercalations, etc. However, there is very limited…
Electrical pulse stimulation drives many important physical phenomena in condensed matter as well as in electronic systems and devices. Often, nanoscopic and mesoscopic mechanisms are hypothesized, but methods to image electrically driven…
The generation of a current by light is a key process in optoelectronic and photovoltaic devices. In band semiconductors, depletion fields associated with interfaces separate long-lived photo-induced carriers. However, in systems with…
The physics of the metal-insulator transition (MIT) in vanadium dioxide remains a subject of intense interest. Because of the complicating effects of elastic strain on the phase transition, there is interest in comparatively strain-free…