Related papers: Attosecond-fast internal photoemission
We present a combined numerical and theoretical study of atomic photoionization in the time domain. We show how a photoelectron wave packet rapidly changes its shape after being emitted, from a complex multi-peak structure to eventually a…
The quasiparticle spectra of atomically thin semiconducting transition metal dichalcogenides (TMDCs) and their response to an ultrafast optical excitation critically depend on interactions with the underlying substrate. Here, we present a…
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…
The cooling of hot electrons in graphene is the critical process underlying the operation of exciting new graphene-based optoelectronic and plasmonic devices, but the nature of this cooling is controversial. We extract the hot electron…
The ability to control electronic properties of a material by externally applied voltage is at the heart of modern electronics. In many cases, it is the so-called electric field effect that allows one to vary the carrier concentration in a…
Highly energetic ions traversing a two-dimensional material such as graphene produce strong electronic excitations. Electrons excited to energy states above the work function can give rise to secondary electron emission, reducing the amount…
Over the past few decades, following the first demonstration of ultrafast electron microscopy, numerous research groups have focused on achieving attosecond temporal resolution in electron microscopy with the goal of imaging electron and…
A one-dimensional (1D) model has been constructed to study the transition of the time-dependent ultrafast laser photo-electron emission from a flat metallic surface to the space charge limited (SCL) current, including the effect of…
Photoelectron interferometry with femto- and atto-second light pulses is a powerful probe of the fast electron wavepacket dynamics, albeit it has practical limitations on the energy resolution. We show that one can simultaneously obtain…
Graphene is promising for nanoscale, efficient, ultra-fast photo- and opto-electronic devices because of its remarkable electrical and optical properties, such as fast electron relaxation and heat dissipation. Here, we realize…
When redox active molecules are covalently tethered to the surface of the n-doped silicon, light induces their oxidation by the semiconductor. To visualize this charge separation we have followed the formation and decay of the surface…
Fluorescence studies of natural photosynthetic complexes on a graphene layer demonstrate pronounced influence of the excitation wavelength on the energy transfer efficiency to graphene. Ultraviolet light yields much faster decay of…
The operation of photoemission electron sources with wavelengths near the photoemission threshold has been shown to dramatically decrease the minimum achievable photocathode emittance, but at the cost of significantly reduced quantum…
In classical optical interferometry, loss and background complicate achieving fast nanometer-resolution measurements with illumination at low light levels. Conversely, quantum two-photon interference is unaffected by loss and background,…
The unusual electrical and optical properties of graphene make it a promising candidate for optoelectronic applications. An important, but as yet unexplored aspect is the role of photo-excited hot carriers in charge and energy transport at…
While silicon has dominated solid-state electronics for more than four decades, a variety of new materials have been introduced into photonics to expand the accessible wavelength range and to improve the performance of photonic devices. For…
We use a frequency-dependent electro-optic technique to measure the hole mobility in small molecule organic semiconductors, such as 6,13 bis(triisopropylsilylethynyl)-pentacene. Measurements are made on semiconductor films in bottom gate,…
The speed of integrated circuits is ultimately limited by the mobility of electrons or holes, which depend on the effective mass in a semiconductor. Here, building on an analogy with electromagnetic metamaterials and transformation optics,…
We study the optical response of a suspended graphene field-effect transistor in magnetic fields of up to 9 T (quantum Hall regime). With an illumination power of only 3 {\mu}W, we measure a photocurrent of up to 400 nA, corresponding to a…
Realistic attosecond wave packets have complex profiles that, in dispersive conditions, rapidly broaden or split into multiple components. Such behaviors are encoded in sharp features of the wave packet spectral phase. Here, we exploit the…