arXiv subjects

A. V. Novikov

Publications and source records attributed to A. V. Novikov.

7 recordsLinked to original sources

arXiv2026

A complete photoluminescence polarization palette from a photonic-crystal slab

Integrated light sources with tailored polarization are essential for integrated photonics, optical communication, sensing, and structured-light applications. However, generating a broad set of polarization states from spontaneous emission usually relies on structures with broken mirror, rotational, or inversion symmetries, or on emitters with predefined polarization properties. Here, we demonstrate a complete photoluminescence polarization palette in a single achiral photonic-crystal slab with a hexagonal lattice of holes and embedded self-assembled Ge(Si) nanoislands. We show that the polarization of the emitted light is governed by the interplay among modes with different symmetries rather than by the properties of unpolarized emitters. Along the high-symmetry directions of the Brillouin zone, symmetry enforces purely linear emission and enables direct polarization-based classification of the photonic-crystal modes. Away from these directions, all Stokes parameters become non-zero, providing full-Stokes control of photoluminescence and highly polarized emission. We further demonstrate polarization vortices associated with symmetry-protected and Friedrich-Wintgen bound states in the continuum, as well as radiating polarization singularities not associated with bound states in the continuum. Through appropriate geometric optimization, the same platform supports photoluminescence with a full polarization palette as well as polarization vortices. Our results establish achiral photonic-crystal slabs as monolithic sources of symmetry-programmable photoluminescence polarization.

physics.optics↗

arXiv2020

Study of the spin-pump-induced inverse spin-Hall effect in Bi doped n-type Si

An inverse spin Hall effect (ISHE) in n-type silicon was observed experimentally when conduction electrons were scattered on the spin-orbit potential of bismuth. The spin current in the silicon layer was generated by excitation of the magnetization precession during ferromagnetic resonance in a thin permalloy (Py) layer deposited on a Si layer doped by phosphor and bismuth. From the angular dependences of the dc voltage for different Py/n-Si:Bi structures aligned along the [011] or [100] crystal axes, we were able to distinguish the planar Hall effect (PHE) and ISHE contributions. The ISHE dc voltage signal was proportional to sinθ*sin2θ product for the structure aligned to the [011] crystal axis and to sinθ*cos2θ for the [100] direction. In addition, the PHE dc voltage was observed for the angles corresponded to the sin2θ dependence. It means that for silicon as a many-valley semiconductor, the scattering of spins due to the spin-orbit potential induced by shallow donor in n-type material is dependent on the orientation of the valley axes relative to the direction of the magnetic field.

cond-mat.mes-hall↗

arXiv2017

Quantitative depth profiling of Si1-xGex structures by time-of-flight secondary ion mass spectrometry and secondary neutral mass spectrometry

Quantification of Ge in Si1-xGex structures (0.092 0.9997) of intensity ratios of GeCs2+/SiCs2+ and 74Ge-/30Si- secondary ions and post-ionized 70Ge+/28Si+ sputtered neutrals with Ge concentration was obtained. The calibration data were used for quantitative depth profiling of [10x(12.3 nm Si0.63Ge0.37/34 nm Si)] structures on Si. Satisfactory compliance of the quantified Ge concentration in SiGe layers with the data measured by high-resolution X-ray diffraction was obtained for both techniques. Both SIMS and SNMS experimental profiles were fitted using the Hofmann mixing-roughness-information depth (MRI) model. In case of TOF-SIMS the quality of the reconstruction was higher than for SNMS since not only the progressing roughening, but also crater effect and other processes unaccounted in the MRI simulation could have significant impact on plasma sputter depth profiling.

cond-mat.mtrl-sci↗

arXiv1999

Enhanced electroweak radiative corrections in SUSY and precision data

Enhanced radiative corrections generated in SUSY extensions of the Standard Model make the fit of the precision data ($Z$-boson decay parameters and $W$-boson mass) worse. This negative effect is washed out for heavy enough squarks due to decoupling property of SUSY models. We find that even for light squarks the enhanced radiative corrections can be small. In this case substantial $\tilde{t}_L \tilde{t}_R$ mixing is necessary.

hep-ph↗

arXiv1998

Enhanced Electroweak Radiative Corrections in SUSY: Gluon-free Observables

Large top quark mass is responsible for the enhancement of the oblique radiative corrections in SUSY models. We present the analytical formulas for these corrections to the $W$-boson mass $m_W$ and to $Z$ $l^+ l^-$ coupling constants. The comparison with the result of the Standard Model fit is made.

hep-ph↗

arXiv1995

Higgs potential bounds on extra quark-lepton generations

We consider the bounds for the values of higgs mass $M_H$ and of the mass of the extra quarks and leptons $M_{extra}$ derived from the stability of vacuum and from the absence of Landau pole in Higgs potential. We find that in the case of the absence of new physics up to the GUT scale the bounds for the mass of the 4th generation are so restrictive that the negative result of CDF search for extra quarks closes the window for fourth generation. In the case of the absence of new physics up to $10^5$ GeV we get weaker but still nontrivial bounds on $M_H$ and $M_{extra}$ as well.

hep-ph↗

arXiv1994

A Simple Way to Estimate the Value of $\barα\equivα(m^2_Z)$

To obtain the value of electromagnetic coupling constant at $q^2=m^2_Z$, $\barα$, which plays a key role in electroweak physics one has to integrate the cross-section of $e^+e^-$-annihilation into hadrons divided by $(s-m^2_Z)$ over $s$ from threshold to infinity. By combining, for each flavor channel, the contribution of lowest resonance with the perturbative QCD continuum, we obtain $1/\barα = 128.90\pm 0.06 $ a result which is close to known result obtained with purely experimental inputs, i.e. $1/\barα = 128.87\pm 0.12$.

hep-ph↗