Nikita Nefedkin

Nikita Nefedkin
CUNY Graduate Center | CUNY

PhD

About

17
Publications
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51
Citations

Publications

Publications (17)
Article
Full-text available
With the development of quantum technologies and their broad applications, the phenomenon of reciprocity breaking has been evolving from an effective tool in classical wave optics and electrodynamics to a promising instrument also for the field of quantum computing and quantum information processing. In this work, nonreciprocal wave phenomena that...
Article
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Engineered intersubband transitions in semiconductor heterostructures featuring multiple quantum wells (MQWs) have been shown to support record-high second-order nonlinear susceptibilities. By integrating these materials in metasurfaces with tailored optical resonances, it is possible to further enhance photonic interactions, yielding giant nonline...
Article
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Recent developments in non-Hermitian physics offer exciting opportunities for a broad range of basic research and engineering applications relevant to the antennas and propagation community. In this article, we offer a tutorial geared toward introducing the unusual electromagnetic phenomena emerging in non-Hermitian systems, with a particular empha...
Article
Optical nanoantennas, i.e., elements transforming localized light or waveguide modes into freely propagating fields and vice versa, are vital components for modern nanophotonics. Optical antennas have been demonstrated to cause the Dicke superradiance effect, i.e., collective spontaneous emission of quantum sources. However, the impact of coherent...
Preprint
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The physics of systems that cannot be described by a Hermitian Hamiltonian, has been attracting a great deal of attention in recent years, motivated by their nontrivial responses and by a plethora of applications for sensing, lasing, energy transfer/harvesting, topology and quantum networks. Electromagnetics is an inherently non-Hermitian research...
Preprint
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Optical supercavity modes (superstates), i.e., hybrid modes emerging from the strong coupling of two nonorthogonal modes of an open cavity, can support ultranarrow lines in scattering spectra associated with quasi bound states in the continuum (quasi-BIC). These modes are of great interest for sensing applications as they enable compact systems wit...
Article
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We theoretically study the role of strong coupling between organic J-aggregated chromophore and a plasmonic nanostructure in the process of photobleaching suppression. We take into account the influence of vibrational degrees of freedom of nuclei in the molecules of J-aggregates in the Born--Markov approximation. We then show that in the strong cou...
Preprint
Full-text available
Optical nanoantennas, i.e., elements transforming localized light or waveguide modes into freely propagating fields and vice versa, are vital components for modern nanophotonics. Recently optical antennas have been demonstrated to cause the Dicke superradiance effect, i.e., collective spontaneous emission of quantum sources. However, the impact of...
Article
Full-text available
Distributed feedback (DFB) lasers exploiting plasmonic structures as cavities are basic elements for various applications from sensorics to optoelectronics. Here, the time response of a plasmonic DFB laser in the small‐signal modulation regime is studied. It is shown that the temporal period of the plasmonic DFB laser response can be equal to an in...
Article
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We study the second-order coherence function of a plasmonic nanoantenna fed by near-field of a single-photon source incoherently pumped in the continuous wave regime. We consider the case of a strong Purcell effect, when the single-photon source radiates almost entirely in the mode of a nanoantenna. We show that when the energy of thermal fluctuati...
Article
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The time response to an external signal is the main characteristic of optoelectronic devices that determines their maximum modulation frequency. The use of plasmonic structures provides the opportunity to significantly reduce the response time. In this paper, we study the temporal dynamics of a plasmonic distributed feedback laser consisting of a t...
Article
An anomalously high photosensitivity of \({\text{Cd}}{{{\text{S}}}_{{{\text{1--}}x}}}{\text{S}}{{{\text{e}}}_{x}}\) granular films observed in the experiment is explained. It is assumed that the charge transfer mechanism based on surface states existing at the granule boundaries can be responsible for an anomalously high photocurrent-to-dark curren...
Article
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Plasmonic distributed-feedback lasers based on a two-dimensional periodic array of metallic nanostructures are the main candidate for nanoscale sources of coherent electromagnetic field. Strong localization of the electromagnetic field and the large radiation surface are good opportunities for achieving an ultrashort response time to the external a...
Article
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In this paper, we consider the nonlinear response to the external electromagnetic field of a plasmonic nanolaser consisting of a metallic nanoparticle interacting with a pumped active medium. We investigate plasmonic nanolaser dynamics in the regime of loss compensation, when at certain values of the magnitude and frequency of the external electrom...
Article
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In this work we consider the dynamics of an ensemble of two-level atoms that interact with finite-width resonator mode. The superradiant burst occurs under a wide range of parameters in such a system. However, if the initial phase distribution of dipole moments of N two-level atoms is random, not all atoms take part in the superradiant process, but...
Article
Full-text available
In 1954, Dicke predicted that a system of quantum emitters confined to a subwavelength volume would produce a superradiant burst. For such a burst to occur, the emitters must be in the special Dicke state with zero dipole moment. We show that a superradiant burst may also arise for non-Dicke initial states with a nonzero dipole moment. Both for Dic...
Article
Full-text available
We suggest a mechanism for the emergence of a superradiance burst in a subwavelength array of nonlinear classical emitters. We assume that the emitters interact via their common field of radiative response and that they may have an arbitrary distribution of initially phases. We show that only if this distribution is not uniform, a non-zero field of...