相关论文: Ultrafast Electron-Lattice Coupling Dynamics in VO…
Multi-pulse nonlinear THz spectroscopies enable a new understanding of interacting metallic systems via their sensitivity to novel correlation functions. Here, we investigated the THz nonlinear properties of the dilute metallic phase of…
Ultrafast optical pump-probe spectroscopy is used to track carrier dynamics in the large magnetoresistance material WTe$_{2}$. Our experiments reveal a fast relaxation process occurring on a sub-picosecond time scale that is caused by…
Controlling electronic population through chemical doping is one way to tip the balance between competing phases in materials with strong electronic correlations. Vanadium dioxide exhibits a first-order phase transition at around 338 K…
Recent experiments suggest that atomic disordering dynamics are more universal than conventional coherent processes in photoinduced phase transitions (PIPTs), yet its mechanism remains unclear. Using real-time time-dependent density…
We have studied ultrafast dynamics of thin films of LaCoO$_3$ and La$_{0.5}$Sr$_{0.5}$CoO$_3$ with femtosecond pump-probe ellipsometry in the energy range of 1.6-3.4 eV. We have observed a large pump-induced transfer of spectral weight in…
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…
Time-domain femtosecond laser spectroscopic measurements of the ultrafast lattice dynamics in 2H-MoTe2 bulk crystals were carried out to understand the carrier-phonon interactions that govern electronic transport properties. An unusually…
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…
Vanadium dioxide (VO2) is a phase change material that can reversibly change between high and low resistivity states through electronic and structural phase transitions. Thus far, VO2 memory devices have essentially been volatile at room…
Impedance spectroscopy measurements were performed in high quality Vanadium dioxide (VO2) thin films. This technique allows us investigate the resistive and capacitive contribution to the dielectric response near the metal-insulator…
Thin films of VO$_2$ on different substrates, Al$_2$O$_3$ and SiO$_2$/Si, have been prepared and characterized from room temperature up to 360 K. From the band structure in the rutile metallic phase and in the monoclinic insulating phase…
We have made a detailed temperature-dependent photoemission study of VO_2/TiO_2(001) thin films, which show a metal-insulator transition at \sim 300 K. Clean surfaces were obtained by annealing the films in an oxygen atmosphere. Spectral…
The pressure driven Mott-transition in Chromium doped V2O3 films is investigated by direct electrical measurements on polycrystalline films with thicknesses down to 10 nm, and doping concentrations of 2%, 5% and 15%. A change in resistivity…
The debate about whether the insulating phases of vanadium dioxide (VO2) can be described by band theory or must be described by a theory of strong electron correlations remains unresolved even after decades of research. Energy-band…
The ultrafast electronic structures of the charge density wave material 1T-TiSe$_2$ were investigated by high-resolution time- and angle-resolved photoemission spectroscopy. We found that the quasiparticle populations drove ultrafast…
Transition metal nitrides are a fascinating class of hard coating material that provide an excellent platform for investigating superconductivity and fundamental electron phonon interactions. In this work the structural morphological and…
First-order phase transitions in solids are notoriously challenging to study. The combination of change in unit cell shape, long range of elastic distortion, and flow of latent heat leads to large energy barriers resulting in domain…
Use of electrode materials that show phase change behavior and hence drastic changes in electrochemical activity during operation, have not been explored for Li-ion batteries. Here we demonstrate the vanadium oxide (VO2) cathode that…
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…
The ultrafast control of materials has opened the possibility to investigate non-equilibrium states of matter with striking properties, such as transient superconductivity and ferroelectricity, ultrafast magnetization and demagnetization,…