Superradiant diamond color center arrays coupled to concave plasmonic nanoresonators

Abstract

authors equally contributed mcsete@physx.u-szeged.hu Different types of concave plasmonic nanoresonators have been optimized to achieve superradiantly enhanced emission of SiV color centers in diamond. Comparative study has been performed to consider advantages of different N number of SiV color centers, different diamond-silver (bare) and diamond-silver-diamond (coated) core-shell nanoresonator types, as well as of spherical and ellipsoidal geometry. The complete fluorescence enhancement (qualified by P x factor) monitoring and the cQE corrected quantum efficiency weighted P x cQE objective function optimization promotes to design bad-cavities for plasmonic Dicke effect. The switching into a collective Dicke state via optimized nanoresonators results in a radiated power proportional to N 2 , which manifest itself in an enhancement proportional to N both of the excitation and emission rates. Accordingly, enhancement proportional to N 2 of the P x factor and P x cQE has been reached both via four and six SiV color centers arranged in symmetrical square and hexagonal patterns inside all types of inspected nanoresonators. Coated spherical and bare ellipsoidal nanoresonators result in stronger noncooperative fluorescence enhancement, while superradiance is better achieved via bare spherical nanoresonators independently of SiV color centers number, and via coated (bare) ellipsoidal nanoresonators seeded by four (six) SiV color centers. Indistinguishable superradiant state of four color centers and line-width narrowing is achieved via bare nanoresonators. Six color centers seeded bare spherical (ellipsoidal) nanoresonators result in larger fluorescence enhancement and more significantly overridden superradiance thresholds, while having slightly more (less) pronounced badcavity characteristics. Both phenomena are simultaneously optimized in ellipsoidal bare nanoresonators embedding six color centers with a slightly larger detuning. IntroductionThe superradiance (SR) predicted first by Dicke has been thoroughly studied throughout the last half-century [1,2]. In case of cooperativity N emitters can exhibit N-times shorter radiative decay, accordingly the maximum rate of emission can be proportional to N 2 . Contradicting predictions also appeared in the primary literature regarding that the coherence can be lost within the expected superradiance lifetime caused by spatially varying frequency shift [3]. However, the principles regarding that Dicke effect can be achieved either via systems, which are initially in excited "collective Dicke" state, or via transient amplification of the photon noise, are widely accepted by the scientific community [4,5]. In sub-wavelength emitter arrays the non-uniform distribution of initial phases is the pre-condition of a superradiant burst [6]. The SR phenomenon has been widely inspected in case of various systems, which are either significantly smaller or larger than the wavelength [7]. Among large-scale superradiant systems the slab geometry with halfwavelength-scaled thickness was thoro...

Plasmonically Enhanced Superradiance of Broken-Symmetry Diamond Color Center Arrays Inside Core-Shell Nanoresonators

“…Our previous studies have revealed that there is a trade-off between the total fluorescence enhancement ( P x factor , defined as the product of the radiative rate enhancements at the excitation ( δR ex ) and emission ( δR em )) and the antenna efficiency that is corrected with the intrinsic SiV color center quantum efficiency at the emission ( cQE ). These studies proved that optimization realized by using the objective function of P x and P x *cQE = P x × cQE product promotes to design efficient non-cooperative fluorescent and superradiant configurations, respectively [ 26 , 55 , 56 ]. Accordingly, we have selected the P x *cQE quantity as the objective function for the present numerical optimization.…”

“…Accordingly, we have selected the P x *cQE quantity as the objective function for the present numerical optimization. The robustness of a method relying on this objective function is due to the relationship between the nanoresonator quality factor ( Q-factor that is proportional to the Purcell factor ) and superradiance, considering that bad-cavity characteristics allow it to achieve a maximal radiative rate, meaning on the level of superradiance [ 55 , 56 ].…”

“…In our previous studies, we have demonstrated how the superradiance of SiV color centers can be plasmonically boosted when they are arranged inside various core-shell nanoresonators in symmetrical arrays [ 55 , 56 ]. The advantages of ellipsoidal geometry, diamond-silver bare composition and a larger number of dipoles have been demonstrated.…”

Quantum Antennas

“…[ 204 ] Supperradiance was experimentally demonstrated both with the NV and the SiV color centers. [ 270,271 ]…”

Optimalizált nanoplazmonika

“…Az ezüst nanorezonátorokkal a gerjesztés is erősíthető, ugyanakkor mindkét fém alkalmas az emisszió erősítésére. Az emisszió erősítése mellett az SiV színcentrum intrinsic kvantumhatásfokánál jobb hatékonyságot mutató csatolt emitter-nanorezonátor rendszerek is tervezhetők specifikus kvantuminformatikai célokra[3,4].2. ábra A vizsgált SNSPD rendszerekben az NbN/Au korrelációja az (a) NbN abszorpció és (b) polarizáció kontraszt értékekkel; (c) az integrált polarizációkontraszt értékek.…”