Theory and Limits of On-Demand Single-Photon Sources Using Plasmonic Resonators: A Quantized Quasinormal Mode Approach

Abstract

Quantum emitters coupled to plasmonic resonators are known to allow enhanced broadband Purcell factors, and such systems have been recently suggested as possible candidates for on-demand single photon sources, with fast operation speeds. However, a true single photon source has strict requirements of high efficiency (brightness) and quantum indistinguishability of the emitted photons, which can be quantified through two-photon interference experiments. To help address this problem, we employ and extend a recently developed quantized quasinormal mode approach, which rigorously quantizes arbitrarily lossy open system modes, to compute the key parameters that accurately quantify the figures of merit for plasmon-based single photon sources. We also present a quantized input-output theory to quantify the radiative and nonradiative quantum efficiencies. We exemplify the theory using a nanoplasmonic dimer resonator made up of two gold nanorods, which yields large Purcell factors and good radiative output beta factors. Considering an optically pulsed excitation scheme, we explore the key roles of pulse duration and pure dephasing on the single photon properties, and show that ultrashort pulses (sub-ps) are generally required for such structures, even for low temperature operation. We also quantify the role of the nonradiative beta factor both for single photon and two-photon emission processes. Our general approach can be applied to a wide variety of plasmon systems, including metal-dielectrics, and cavity-waveguide systems, without recourse to phenomenological quantization schemes.

Ultrafast quantum photonics enabled by coupling plasmonic nanocavities to strongly radiative antennas

“…If such high emission rates are achieved, one must ensure that the emitter is pumped into the excited state with a rate even higher than its decay rate, which appears to be problematic due to several practical reasons [29]. Whether the plasmonic electron motion will contribute to dipole dephasing in ultra-small plasmonic cavities remains to be studied.…”

“…At the same time, γ opt ff depends weakly on the intrinsic emission rate γ 0 . One would need to employ a more rigorous approach to quantify the decay rates near plasmonic nanostructures more precisely [27][28][29][30]. However, our order-ofmagnitude analysis provides intuitive insight into the operation of emitter-cavity-antenna systems without involving the full-wave simulations presented below or more complex analytical methods.…”

Efficient Pulse‐Excitation Techniques for Single Photon Sources from Quantum Dots in Optical Cavities

“…We also quantify the indistinguishability by simulation of a Hong-Ou-Mandel twophoton interference experiment, as in ref. [38]…”

Quantized quasinormal-mode description of nonlinear cavity-QED effects from coupled resonators with a Fano-like resonance

“…Recently, the approach from Ref. [41] was applied to accurately describe single-photon emission in a single-mode metal resonator [45] and was also used to model the photonic mode quantization for molecular optomechanics in a hybrid metaldielectric resonator [23]. In the first case, a cavity output field expression for the single QNM was derived, which is the basis to determine correlation functions and light statistics of the resonator-emitter system, important to simulate quantum optical experiments such as the Hong-Ou-Mandel [46] or Hanbury-Brown-Twiss [47] setups.…”

“…This separation is essential to describe a realistic input-output formalism in cases of absorptive lossy structures, where the output is usually treated in the same way as for systems with only radiative losses [48][49][50]. While in the single-mode case, the results from a more phenomenological dissipative JC model is modified by a loss-induced prefactor, which separates between radiative and nonradiative decay [45], there are additional changes in the multimode case due to off-diagonal mode interaction, which influences the output coupling. This may also effect the behavior of multimode systems in higher rungs of the JC ladder, e.g., the change of Poissionian to sub-Possionian light when coupling a resonator-emitter system to another resonator, which is often described with two uncoupled modes [51,52].…”