arXiv subjects

Vsevolod Salakhutdinov

Publications and source records attributed to Vsevolod Salakhutdinov.

4 recordsLinked to original sources

arXiv2026

On Optimal Measurement-State Preparation via Geometric Transport of the Squeezing Ellipse

Preparation of optimal measurement states is a key requirement in quantum metrology utilizing squeezed states. We discuss a geometric framework that transforms an initially misaligned squeezed input into a measurement-optimal state in SU(2)-symmetric systems. Within this framework, the orientation of the squeezing ellipse constitutes an additional geometric degree of freedom and evolves as the mean state follows a controlled trajectory on the unit sphere. The resulting rotation of the ellipse is determined by the geometry of the path and, for the relevant class of transformations, depends on the solid angle enclosed by the trajectory, establishing a connection with the geometric phase. The discussed framework is applicable to different physical platforms. As a particular example, we consider polarization-squeezed light and outline a possible implementation using a continuously varying birefringent element.

quant-ph↗

arXiv2026

Mie resonances in optical trapping: Their role in kinematics and back-action

The heating rate plays a crucial role in the decoherence of the harmonic motion of an optically levitated nanoparticle. The values of this rate vary depending on both the scattering photon rate and the kinetic energy acquired through individual photon recoils. While the combined roles of these factors have been extensively studied, the energy transfer per recoil has not been explicitly examined. This energy transfer is often approximated using a linear dipole model with coefficients $\{1/5, 2/5, 7/5\}$ which applies in the Rayleigh limit. In this work, we analyze the evolution of energy transfer per photon recoil for low-absorption dielectric nanospheres with diameters ranging from 2 nm to 500 nm. Using a far-field approximation, we demonstrate that the Kerker condition, which enhances the alignment between incident and scattered wavevectors, may significantly reduce the energy transferred per recoil. Although this reduction is counterbalanced by the increasing scattering rate, for an individual scattering event, the reduction of recoil suggests an intrinsic suppression of back-action. Our results reveal a potential enhancement in the accuracy of estimations in tabletop experiments involving Mie particles of the considered sizes and provide guidance for the selection of optimal probe sizes and materials. Our interpretation of recoil reduction as a manifestation of back-action suppression indicates a potential pathway toward minimizing measurement-induced disturbances through engineered control of scattering directivity, potentially enabled by metamaterial-based designs.

physics.optics↗

arXiv2020

Single photons emitted by nano-crystals optically trapped in a deep parabolic mirror

We investigate the emission of single photons from CdSe/CdS dot-in-rods which are optically trapped in the focus of a deep parabolic mirror. Thanks to this mirror, we are able to image almost the full 4$π$ emission pattern of nanometer-sized elementary dipoles and verify the alignment of the rods within the optical trap. From the motional dynamics of the emitters in the trap we infer that the single-photon emission occurs from clusters comprising several emitters. We demonstrate the optical trapping of rod-shaped quantum emitters in a configuration suitable for efficiently coupling an ensemble of linear dipoles with the electromagnetic field in free space.

quant-ph↗

arXiv2016

Optical trapping of nanoparticles by full solid-angle focusing

Optical dipole-traps are used in various scientific fields, including classical optics, quantum optics and biophysics. Here, we propose and implement a dipole-trap for nanoparticles that is based on focusing from the full solid angle with a deep parabolic mirror. The key aspect is the generation of a linear-dipole mode which is predicted to provide a tight trapping potential. We demonstrate the trapping of rod-shaped nanoparticles and validate the trapping frequencies to be on the order of the expected ones. The described realization of an optical trap is applicable for various other kinds of solid-state targets. The obtained results demonstrate the feasibility of optical dipole-traps which simultaneously provide high trap stiffness and allow for efficient interaction of light and matter in free space.

physics.optics↗