Related papers: Observed enhanced emission at higher-order excepti…
We derive a new expression for the two-photon spontaneous emission (TPSE) rate of an excited quantum emitter in the presence of arbitrary bodies in its vicinities. After investigating the influence of a perfectly conducting plate on the…
We study Fermi edge singularities in photo-absorption spectra of generic mesoscopic systems such as quantum dots or nanoparticles. We predict deviations from macroscopic-metallic behavior and propose experimental setups for the observation…
We present a simple derivation of the density of states (DOS) in confined nanomaterials. While previous studies often apply a heuristic $L^{3-d}$ confinement factor to bulk DOS expressions, we show that this factor arises naturally from a…
The resonance, a collective boson mode, was usually thought to be a possible glue of superconductivity. We argue that it is rather a natural product of the \emph{d}-wave pairing and the Fermi surface topology. A universal scaling…
Exceptional point (EP) degeneracies in coupled cavities with gain and loss provide on-chip photonic devices with unconventional features and performance. However, such systems with realistic structures often miss the exact EPs even in…
Quantum emitters of single indistinguishable photons play a key role in quantum technologies. Among condensed matter systems, colloidal perovskite quantum dots have emerged as promising candidates, exhibiting high-purity single photon…
For the BCS theory of superconductivity, the electron-phonon interaction is transformed to an attractive electron-electron interaction in the vicinity of the Fermi energy only. At the same time, its formal derivation using a unitary…
In this paper we discuss the magnetic Purcell effect of a magnetic dipole near a semi-infinite antiferromagnet. Contrary to the electric Purcell effect, the magnetic one is not so well studied in the literature. We derive the dispersion…
The parametric amplification of ultrashort (femtosecond) laser pulses in crystals with a regular domain structure (RDS) of the 5%Mg : PPLN type has been investigated theoretically. The focus was on the formation of a signal pulse in…
Fibers lasers is a field which is typically dominated by rare earth ions as gain material in the core of a silica optical waveguide. Due to their specific emission wavelengths, rare-earth doped fiber lasers are available only at few…
A one-dimensional photonic-crystal (PC) cavity with nanoholes is proposed for extremely enhancing the THz electric fields by utilizing the electromagnetic (EM) boundary conditions, where both slot effect (for the perpendicular component of…
A reduced-density-matrix (RDM)-based approach to {\em ab initio} cavity quantum electrodynamics (QED) is developed. The expectation value of the Pauli-Fierz Hamiltonian is expressed in terms of one- and two-body electronic and photonic…
Exceptional points, resulting from non-Hermitian degeneracies, have the potential to enhance the capabilities of quantum sensing. Thus, finding exceptional points in different quantum systems is vital for developing such future sensing…
We investigate the exceptional points (EPs) and their pseudospectra in black hole perturbation theory. By considering a Gaussian bump modification to the Regge-Wheeler potential with variable amplitude, position, and width parameters,…
In non-Hermitian band structures, exceptional points generically form gapless lines or loops that give rise to extensively many defective eigenstates. In this work, we investigate how they nontrivially contribute to higher-order nonlinear…
Exceptional points (EPs), at which both eigenvalues and eigenvectors coalesce, are ubiquitous and unique features of non-Hermitian systems. Second-order EPs are by far the most studied due to their abundance, requiring only the tuning of…
Localized surface plasmon resonances have recently attracted considerable attention due to their ability to dramatically enhance near-field optical intensities and boost nanoscale light-matter interactions. Here we demonstrate unambiguously…
We show that the local density of states (LDOS) of a wide class of tight-binding models has a weak body-order expansion. Specifically, we prove that the resulting body-order expansion for analytic observables such as the electron density or…
We theoretically investigate the spontaneous emission of a point--like dipolar emitter located near a two--dimensional (2D) plasmonic waveguide of arbitrary form. We invoke an explicite link with the density of modes of the waveguide…
The Fermi surfaces (FS) of LaOFeAs (in $k_z$=0 plane) consist of two hole-type circles around $\Gamma$ point, which do not touch each other, and two electron-type co-centered ellipses around M point, which are degenerate along the M-X line.…