Related papers: Photoinduced multistage phase transitions in Ta2Ni…
Exciting electrons in solids with intense light pulses offers the possibility of generating new states of matter through nonthermal means and controlling their macroscopic properties on femto- to picosecond timescales. One way to manipulate…
An intense femtosecond-laser excitation of a solid induces highly nonthermal conditions. In materials like silicon, laser-induced bond-softening leads to a highly incoherent ionic motion and eventually nonthermal melting. But is this…
The formation of excitonic insulator phases in quantum materials is often masked by structural distortions caused by the coupling between electronic and phononic order parameters. Here we show that the candidate material Ta$_2$NiSe$_5$ is…
Laser excitation has emerged as an effective tool for probing microscopic interactions and manipulating phases of matter. Among charge density wave (CDW) materials, 1T-TaS2 has garnered significant attention due to its diverse stacking…
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…
We report on an ultrafast photoinduced phase transition with a strikingly long-lived Martensitic anomaly driven by above-threshold single-cycle terahertz (THz) pulses in Nb$_3$Sn. A non-thermal, THz-induced depletion of low frequency…
Assembling transition metal dichalcogenides (TMDCs) at the two-dimensional (2D) limit is a promising approach for tailoring emerging states of matter such as superconductivity or charge density waves (CDWs). Single-layer (SL) VSe$_2$ stands…
Layered tin selenide (SnSe) has recently emerged as a high-performance thermoelectric material with the current record for the figure of merit (ZT) observed in the high-temperature Cmcm phase. So far, access of the Cmcm phase has been…
To understand complex physics of a system with strong electron electron interactions, it is ideal to control and monitor its properties while tuning an external electric field applied to the system. Indeed, complete electric field control…
Light-manipulation of correlated electronic phases in solids offers the tantalizing prospect of realizing electronic devices operating at the ultrafast time-scale. In this context, the experimental realization of non-equilibrium transitions…
Photoexcitation is a powerful means in distinguishing different interactions and manipulating the states of matter, especially in complex quantum systems. As a well-known charge density wave (CDW) material, 1T-TaS2 has been widely studied…
We report on the nonequilibrium dynamics of the electronic structure of the layered semiconductor Ta$_2$NiSe$_5$ investigated by time- and angle-resolved photoelectron spectroscopy. We show that below the critical excitation density of…
The transition metal chalcogenide Ta$_2$NiSe$_5$ undergoes a second-order phase transition at $T_c=328$ K involving a small lattice distortion. Below $T_c$, a band gap at the center of its Brillouin zone increases up to about 0.35 eV. In…
Dynamic control of conductivity and optical properties via atomic structure changes is of tremendous technological importance in information storage. Energy consumption considerations provide a driving force toward employing thin materials…
We present a first-principles study based on density functional theory (DFT) on the electronic and structural properties of Ta2NiSe5, a layered transition metal chalcogenide that has been considered as a possible candidate for an excitonic…
Femto-second techniques addressing phase transitions induced by optical pumps have allowed recently to put an ambitious goal to attend hidden states which are inaccessible and even unknown under equilibrium conditions. Recently (*), the…
Recently, two-dimensional materials and in particular transition metal dichalcogenides (TMDs) were extensively studied because of their strong light-matter interaction and the remarkable optoelectronic response of their field-effect…
We present a generic procedure for quantifying the interplay of electronic and lattice degrees of freedom in photo-doped insulators through a comparative analysis of theoretical many-body simulations and time- and angle-resolved…
Microscopic and dynamic control over quantum states is essential for bridging fundamental studies of material properties to device function. Realizing such control at combined high spatial resolution and ultrafast temporal precision remains…
Despite inherently poor interlayer conductivity, photodetectors made from few-layer devices of 2D transition metal dichalcogenides (TMDs) such as WSe$_2$ and MoS$_2$ can still yield a desirably fast ($\leq$90 ps) and efficient…