Searcharxiv⌕ Search

arXiv subjects

Ivan V. Panyukov

Publications and source records attributed to Ivan V. Panyukov.

6 recordsLinked to original sources

The influence of strong coupling between single-photon source and spectral filter on photon statistics

One of the most common approaches for coupling optical single-photon sources and photonic integrated circuits is to use a cavity. The cavity acts as a spectral filter that distorts the light spectrum and changes its statistical properties. But in the general case one should take into account not only spectral filtering of light but also the spectral filter influence on the single-photon source dynamics. We build an effective analytical model for description of the cavity influence on the photon statistics of light emitted by the single-photon source as spectral filtering only. We show that this model correctly describes the photon statistics even in a strong-coupling regime between the single-photon source and the spectral filter. Our results can be useful for analytical modeling of photon statistics of quantum emitters strongly coupled to various electromagnetic interfaces.

quant-ph↗

Stokes-anti-Stokes correlations of light propagating through weakly guiding optical fiber

Statistical properties of light produced in spontaneous Raman scattering on an ensemble of molecules indicate the quantum nature of this phenomenon. The scattered light is non-classical and has high non-classical intensity correlations between Stokes and anti-Stokes components. The temporal coherence of this light is well investigated, while many questions related to spatial coherence remain open. Recent experiments reveal two peculiar features of the spatial coherence of the Stokes and anti-Stokes light. First, the intensity correlations between Stokes and anti-Stokes light remain non-classical even for macroscopic samples containing many molecules. Second, these correlations decrease when signal propagates through a multi-mode optical fiber: the more propagating fiber modes at Stokes and anti-Stokes frequencies the less the correlations. Moreover, the second-order autocorrelation function of Stokes and anti-Stokes light also decreases with the number of propagating modes in multi-mode fiber. In this paper, we build a model of spontaneous Raman scattering correlations of light produced by an ensemble of molecules and propagating through weakly guiding optical fiber that quantitatively explains all these observations. We show that spacial orthogonality of the fiber modes makes the light propagating through these modes uncorrelated in the standard detection scheme. This leads to suppression of non-classical intensity correlations of the total field in the multi-mode fiber. We find the degree of non-classical correlations on fiber parameters. The obtained results pave the way for engineering of non-classical Stokes -- anti-Stokes correlations.

physics.optics↗

Thermalization in Quantum Fluids of Light: A Convection-Diffusion Equation

We develop a microscopic theory for the dynamics of quantum fluids of light, deriving an effective kinetic equation in momentum space that takes the form of the convection-diffusion equation. In the particular case of two-dimensional systems with parabolic dispersion, it reduces to the Bateman--Burgers equation. The hydrodynamic analogy unifies nonlinear wave phenomena, such as shock wave formation and turbulence, with non-equilibrium Bose--Einstein condensation of photons and polaritons in optical cavities. We introduce the Reynolds number $(\textit{Re})$ and demonstrate that the condensation threshold corresponds exactly to a critical Reynolds number of unity $(\textit{Re}=1)$, beyond which $(\textit{Re} > 1)$ a shock-like front emerges in the momentum space, characterized by the Bose--Einstein distribution for the particle density in states with high momentum.

cond-mat.quant-gas↗

Thermalization rate of polaritons in strongly-coupled molecular systems

Polariton thermalization is a key process in achieving light-matter Bose--Einstein condensation, spanning from solid-state semiconductor microcavities at cryogenic temperatures to surface plasmon nanocavities with molecules at room temperature. Originated from the matter component of polariton states, the microscopic mechanisms of thermalization are closely tied to specific material properties. In this work, we investigate polariton thermalization in strongly-coupled molecular systems. We develop a microscopic theory addressing polariton thermalization through electron-phonon interactions (known as exciton-vibration coupling) with low-energy molecular vibrations. This theory presents a simple analytical method to calculate the temperature-dependent polariton thermalization rate, utilizing experimentally accessible spectral properties of bare molecules, such as the Stokes shift and temperature-dependent linewidth of photoluminescence, in conjunction with well-known parameters of optical cavities. Our findings demonstrate qualitative agreement with recent experimental reports of nonequilibrium polariton condensation in both ground and excited states, and explain the thermalization bottleneck effect observed at low temperatures. This study showcases the significance of vibrational degrees of freedom in polariton condensation and offers practical guidance for future experiments, including the selection of suitable material systems and cavity designs.

quant-ph↗

Adjoint master equation for multi-time correlators

The quantum regression theorem is a powerful tool for calculating the muli-time correlators of operators of open quantum systems which dynamics can be described in Markovian approximation. It enables to obtain the closed system of equation for the multi-time correlators. However, the scope of the quantum regression theorem is limited by a particular time order of the operators in multi-time correlators and does not include out-of-time-ordered correlators. In this work, we obtain an adjoint master equation for multi-time correlators that is applicable to out-of-time-ordered correlators. We show that this equation can be derived for various approaches to description of the dynamics of open quantum systems, such as the global or local approach. We show that the adjoint master equation for multi-time correlators is self-consistent. Namely, the final equation does not depend on how the operators are grouped inside the correlator, and it coincides with the quantum regression theorem for the particular time ordering of the operators.

quant-ph↗

Controlling Purity, Indistinguishability and Quantum Yield of Incoherently Pumped Two-Level System by Spectral Filters

Dephasing processes significantly impact the performance of deterministic single-photon sources. Dephasing broadens the spectral line and suppresses the indistinguishability of the emitted photons, which is undesirable for many applications, primarily for quantum computing. We consider a light emitted by a two-level system with a pulsed incoherent pump in the presence of the spectral filter. The spectral filter allows control of the second-order autocorrelation function, indistinguishability, and quantum yield. We show that narrow spectral filters can increase the indistinguishability of the emitted light while undermining the quantum yield. The influence of the spectral filter on the second-order correlation function depends on the duration of the pump. When the pumping pulse is long compared to the lifetime of the two-level system, the narrow spectral filters lead to a rapid increase in the second-order autocorrelation function. In this limit, the statistics of the light from the two-level system inherit the statistics of the incoherent pump. In the case of the short duration of the pump pulse, it is possible to preserve single-photon properties to some degree for the sub-lifetime width of the spectral filter. Moreover, when the light emitted by the single-photon source is used to control a quantum system, e.g., cavity, the single-photon properties of the light manifest themselves differently, depending on the response time of the quantum system. In particular, in the case of long response time, the spectral filter with sub-lifetime width can provide the near-zero second-order autocorrelation function.

quant-ph↗