arXiv subjects

Sergey V. Polyakov

Publications and source records attributed to Sergey V. Polyakov.

12 recordsLinked to original sources

arXiv2025

Picosecond synchronization of mode-locked lasers for metropolitan-scale quantum networks

We demonstrate picosecond-level synchronization of two actively mode-locked Ti:Sapphire lasers via the White Rabbit Precision Time Protocol (WR-PTP), tested over 120 km of deployed optical fiber. This synchronization capability, in combination with the highly single-mode, transform-limited pulses produced by each laser, enables their use as pump lasers for indistinguishable photon sources at remote locations in a quantum network. Here, the WR-PTP serves as a scalable network synchronization protocol, and its performance is compared to traditional methods of local synchronization. We demonstrate pulse-to-pulse synchronization better than 3 ps and time deviation (TDEV) values below 4 ps for all averaging times up to 10 s. With a designed coherence time of 35 ps for single photon sources utilizing these lasers, the achievable temporal overlap corresponds to 98 % Hong-Ou-Mandel (HOM) interference visibility between independent sources.

quant-ph↗

arXiv2024

Quantum plasmonic sensing by Hong-Ou-Mandel interferometry

We propose a quantum plasmonic sensor using Hong-Ou-Mandel (HOM) interferometry that measures the refractive index of an analyte, embedded in a plasmonic beam splitter composed of a dual-Kretschmann configuration, which serves as a frustrated total internal reflection beamsplitter. The sensing performance of the HOM interferometry, combined with single-photon detectors, is evaluated through Fisher information for estimation of the refractive index of the analyte. This is subsequently compared with the classical benchmark that considers the injection of a coherent state of light into the plasmonic beamsplitter. By varying the wavelength of the single photons and the refractive index of the analyte, we identify a wide range where a 50 % quantum enhancement is achieved and discuss the observed behaviors in comparison with the classical benchmark. We expect this study to provide a useful insight into the advancement of quantum-enhanced sensing technologies, with direct implications for a wide range of nanophotonic beamsplitter structures.

quant-ph↗

arXiv2022

Mode structure reconstruction by detected and undetected light

We introduce a novel technique for the reconstruction of multimode optical fields, based on simultaneously exploiting both the generalized Glauber's $K^{th}$-order correlation function $g^{(K)}$ and a recently proposed anti-correlation function (dubbed $θ^{(K)}$) which is resilient to Poissonian noise. We experimentally demonstrate that this method yields mode reconstructions with higher fidelity with respect to those obtained with reconstruction methods based only on $g^{(K)}$'s, even requiring less "a priori" information. The reliability and versatility of our technique make it suitable for a widespread use in real applications of optical quantum measurement, from quantum information to quantum metrology, especially when one needs to characterize ensembles of single-photon emitters in the presence of background noise (due, for example, to residual excitation laser, stray light, or unwanted fluorescence).

quant-ph↗

arXiv2019

Electromagnetically induced transparency in inhomogeneously broadened solid media

We study, theoretically and experimentally, electromagnetically induced transparency (EIT) in two different solid-state systems. Unlike many implementations in homogeneously broadened media, these systems exhibit inhomogeneous broadening of their optical and spin transitions typical of solid-state materials. We observe EIT lineshapes typical of atomic gases, including a crossover into the regime of Autler-Townes splitting, but with the substitution of the inhomogeneous widths for the homogeneous values. We obtain quantitative agreement between experiment and theory for the width of the transparency feature over a range of optical powers and inhomogeneous linewidths. We discuss regimes over which analytical and numerical treatments capture the behavior. As solid-state systems become increasingly important for scalable and integratable quantum optical and photonic devices, it is vital to understand the effects of the inhomogeneous broadening that is ubiquitous in these systems. The treatment presented here can be applied to a variety of systems, as exemplified by the common scaling of experimental results from two different systems.

quant-ph↗

arXiv2017

Simultaneous, full characterization of a single-photon state using semiconductor quantum-dot light

As single-photon sources become more mature and are used more often in quantum information, communications and measurement applications, their characterization becomes more important. Single-photon-like light is often characterized by its brightness, and two quantum properties: the single-photon composition and the photon indistinguishability. While it is desirable to obtain these quantities from a single measurement, currently two or more measurements are required. Here, we simultaneously determine the brightness, the single photon purity, the indistinguishability, and the statistical distribution of Fock states to third order for a quantum light source. The measurement uses a pair of two-photon (n = 2) number-resolving detectors. n > 2 number-resolving detectors provide no additional advantage in the single-photon characterization. The new method extracts more information per experimental trial than a conventional measurement for all input states, and is particularly more e cient for statistical mixtures of photon states. Thus, using this n=2, number- resolving detector scheme will provide advantages in a variety of quantum optics measurements and systems.

quant-ph↗

arXiv2014

Experimental Bounds on Classical Random Field Theories

Alternative theories to quantum mechanics motivate important fundamental tests of our understanding and descriptions of the smallest physical systems. Here, using spontaneous parametric downconversion as a heralded single-photon source, we place experimental limits on a class of alternative theories, consisting of classical field theories which result in power-dependent normalized correlation functions. In addition, we compare our results with standard quantum mechanical interpretations of our spontaneous parametric downconversion source over an order of magnitude in intensity. Our data match the quantum mechanical expectations, and do not show a statistically significant dependence on power, limiting on quantum mechanics alternatives which require power-dependent autocorrelation functions.

quant-ph↗

arXiv2013

Experimental Test of an Event-Based Corpuscular Model Modification as an Alternative to Quantum Mechanics

We present the first experimental test that distinguishes between an event-based corpuscular model (EBCM) [H. De Raedt et al.: J. Comput. Theor. Nanosci. 8 (2011) 1052] of the interaction of photons with matter and quantum mechanics. The test looks at the interference that results as a single photon passes through a Mach-Zehnder interferometer [H. De Raedt et al.: J. Phys. Soc. Jpn. 74 (2005) 16]. The experimental results, obtained with a low-noise single-photon source [G. Brida et al.: Opt. Expr. 19 (2011) 1484], agree with the predictions of standard quantum mechanics with a reduced $χ^2$ of 0.98 and falsify the EBCM with a reduced $χ^2$ of greater than 20.

quant-ph↗

arXiv2012

Dynamics of the non-classical light from a single solid-state quantum emitter

We measure the dynamics of a non-classical optical field using two-time second-order correlations in conjunction with pulsed excitation. The technique quantifies single-photon purity and coherence during the excitation-decay cycle of an emitter, illustrated here using a quantum dot. We observe that for certain pump wavelengths, photons detected early in the cycle have reduced single-photon purity and coherence compared to those detected later. A model indicates that the single-photon purity dynamics are due to exciton recapture after initial emission and within the same pulse cycle.

quant-ph↗

arXiv2011

Coalescence of Single Photons Emitted by Disparate Single Photon Sources: The Example of InAs Quantum Dots and Parametric Down-Conversion Sources

Single photons produced by fundamentally dissimilar physical processes will in general not be indistinguishable. We show how photons produced from a quantum dot and by parametric down-conversion in a nonlinear crystal can be manipulated to be indistinguishable. The measured two-photon coalescence probability is 16%, and is limited by quantum-dot decoherence. Temporal filtering to the quantum dot coherence time and accounting for detector time response increases this to 61% while retaining 25% of the events. This technique can connect different elements in a scalable quantum network.

quant-ph↗

arXiv2010

Analytical method for parameterizing the random profile components of nanosurfaces imaged by atomic force microscopy

The functional properties of many technological surfaces in biotechnology, electronics, and mechanical engineering depend to a large degree on the individual features of their nanoscale surface texture, which in turn are a function of the surface manufacturing process. Among these features, the surface irregularities and self-similarity structures at different spatial scales, especially in the range of 1 to 100 nm, are of high importance because they greatly affect the surface interaction forces acting at a nanoscale distance. An analytical method for parameterizing the surface irregularities and their correlations in nanosurfaces imaged by atomic force microscopy (AFM) is proposed. In this method, flicker noise spectroscopy - a statistical physics approach - is used to develop six nanometrological parameters characterizing the high-frequency contributions of jump- and spike-like irregularities into the surface texture. These contributions reflect the stochastic processes of anomalous diffusion and inertial effects, respectively, in the process of surface manufacturing. The AFM images of the texture of corrosion-resistant magnetite coatings formed on low-carbon steel in hot nitrate solutions with coating growth promoters at different temperatures are analyzed. It is shown that the parameters characterizing surface spikiness are able to quantify the effect of process temperature on the corrosion resistance of the coatings. It is suggested that these parameters can be used for predicting and characterizing the corrosion-resistant properties of magnetite coatings.

physics.chem-ph↗

arXiv2010

Interference of Single Photons from Two Separate Semiconductor Quantum Dots

We demonstrate and characterize interference between discrete photons emitted by two separate semiconductor quantum dot states in different samples excited by a pulsed laser. Their energies are tuned into resonance using strain. The photons have a total coalescence probability of 18.1% and the coincidence rate is below the classical limit. Post-selection of coincidences within a narrow time window increases the coalescence probability to 47%. The probabilities are reduced from unity because of dephasing and the postselection value is also reduced by the detector time response.

quant-ph↗

arXiv2008

Improved implementation of nonclassicality test for a single particle

Recently a test of nonclassicality for a single qubit was proposed [R. Alicki and N. Van Ryn, J. Phys. A: Math. Theor. 41, 062001 (2008)]. We present an optimized experimental realization of this test leading to a 46 standard deviation violation of classicality. This factor of 5 improvement over our previous result was achieved by moving from the infrared to the visible where we can take advantage of higher efficiency and lower noise photon detectors.

quant-ph↗