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The discovery of intersubband transitions in III-V semiconductor heterostructures [I] had a huge impact on large parts of the condensed matter physics community and ultimately led to the development of quantum well infrared photodetectors [2] and quantum cascade lasers [3]. One of the main constraints, however, are the strict lattice matching conditions of the heterostructures — limiting the available...
Remarkable advances in cooling and manipulating atomic gases have opened up new avenues to explore fundamental concepts in quantum many-body physics. Synthetically created potentials and control of atom-atom interactions have made it possible to tailor the properties of experimental systems at a microscopic level. This led to the concept of quantum simulation — here a system capable of reproducing...
The state of polarization of light is strongly affected by anisotropy and exotic polarization phenomena can be observed in systems where this anisotropy emerges on symmetric and ordered structures on the wavelength scale, as occurs in metamaterials [1, 2] and periodically-poled multiferroic media [3]. In recent studies, conditions have been found in which the dipolar mosaic characterizing disordered...
Inverted Type-I quantum rings (QRs) are a recently developed class of nanostructure in which a lower bandgap material is laterally grown as a crown of same thickness around a higher bandgap nanoplatelet (NPL) core [l·2]· e.g. core/crown CdS/CdSe as shown in Fig. 1(a). For this work, we have colloidally synthesized 3 monolayer (ML) thick CdS/CdSe QR samples using seed-mediated method, by using 3ML...
Surface plasmons resonances occur when a metallic nano-particle is excited by an external electric field. Within the quasi-static limit, Ouyang and Isaacson [1] have shown that the plasmon modes are the solutions of an eigenvalue problem. This boundary element method (BEM) [2] has been extensively used to compute nano-particle plasmon resonances [3,4]. Depending on the geometry of the particle, the...
Solving large optimization problems lies at heart of modem science and technology from social sciences to technological applications, i.e. protein design [1]. Recently, we proposed a new platform for an analog Hamiltonian simulator based on polariton graphs [2], which benefit from continuous read-out and single site control. Ability to control and engineer a wide range of strengths of coupling interactions...
Optically confined structure is a fundamental topic in both basic and applied physics including potential application in information engineering, biological and medical sciences, sensing. In this scenario one-dimensional photonic crystals have been widely investigated and still remain an outstanding tool for new photonics, being the simplest system to exhibit a so-called photonic bandgap and therefore...
Terahertz (THz) and sub-THz frequency emitter-detector technology is receiving increasing attention because of key apphcations in several fields. In particular, ultrafast THz receivers are desired for compact, ultrafast spectroscopy and communication systems. While most of the available THz detectors (thermal, FET …) are currently limited in response time by slow thermal processes and/or by the read-out...
We present results of polarization-resolved differential transmission experiments, in which pump and probe pulses are quasi-resonant with charged and neutral excitons in monolayer WSe2. By selecting co- and cross-circular polarization configurations for pump and probe pulses, the excitations in the K and K' valleys can be individually addressed [1]. From far above the band edge excited pump-probe...
Field localization by nanostructures illuminated with laser pulses of well-defined waveform enables spatial-temporal tailoring of the near-fields for sub-cycle control of electron dynamics at the nanoscale [1]. Transition from the ponderomotive to sub-cycle acceleration regime of the near-field-driven electron emission was shown to be determined by the ratio of the near-field decay length and amplitude...
Parametric downconversion (PDC) allows the generation of highly coherent, spectrally pure single photons for quantum photonics. In a typical heralded PDC source, the signal photon emerges in a spectrally mixed state due to strong (anti)correlation in the joint spectrum of PDC photon pairs.
Demonstrations of quantum key distribution (QKD) [1] with moving platforms are important to prove the viability of future satellite implementations. Thus far these demonstrations of QKD to aircraft have operated exclusively in the downlink configuration [2, 3], where the quantum source and transmitter are placed on the airborne platform. While this approach has the potential for higher key rates,...
Highly nonlinear spatial-temporal patterns are inevitable features of lasing in the low-Q (bad) cavities where a photon lifetime, TE, is less than a polarization relaxation time (a lifetime of the optical dipole oscillations), T2, of the individual active centers excited by pumping [1]. A theoretical analysis of the spatial-temporal dynamics of the field and its spectral and correlation features in...
Squeezed states of light are referred to as non-classical field states and are known to be characterized by strong correlations between photons both in the spectral and spatial domain. For these reasons they are very perspective for many important and interesting practical applications in modern quantum optics including storage and transfer of quantum information. From this point of view multiphoton...
Recently, we have showed a direct laser writing method that exploits nonlinear interactions to form subsurface modifications in silicon. Here, we use the technique to demonstrate laser-slicing of silicon and its applications.
Filamentation of Mid-IR pulses in ambient air is significantly more complicated and challenging as compared to near-IR filaments, due the changing sign of dispersion in the vicinity of 3.6 μm, substantially lower ionization rates and hence plasma density [1], as well as because of the presence of molecular resonances around the atmospheric transparency windows. Experimental observations reveal that...
Recently we have shown that a nanofiber excited by a localized electric source can have enhanced electric and magnetic response depending of the relative orientation of the source and the fiber [1]. We have demonstrated that the dielectric nanofiber can suppress the electric response and enhance the magnetic response of the coupled system when excited with an electric dipole oriented along the circumference...
Similar to their plasmonic counterparts, dielectric nanoantennas have the ability to manipulate the emission properties of nanoscale emitters placed in their vicinity. Most importantly, they can increase the radiative decay rate of emitters by coupling to Mie-type resonances and/or shape the emission into directional patterns [1]. While considerable theoretical work has been dedicated to the study...
Strong light-matter interaction leads to the appearance of new states, i.e. exciton-polaritons, with photophysical properties rather distinct from their constituents. Recent developments in fabrication techniques allow us to make metallic structures with strong electric field confinement in nanoscale mode volumes, allowing for a facile assembly of strongly coupled systems at room temperature based...
Molecules selectively transform light energy from the sun into other forms of energy like heat, electricity, or chemical energy with high quantum efficiency. The energy conversion process is the result of a correlated motion of electrons and nuclei after photoexcitation, often under breakdown of the Born-Oppenheimer approximation. The element and site selectivity of x-rays allows observing molecular...
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