发表机构
University of Central Florida; U.S. Naval Research Laboratory（中佛罗里达大学; 美国海军研究实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究建立量子电动力学理论，实现栅极可调导体-介质-导体异质结构中自发辐射与FRET的通用调控，揭示不同反射振幅下的FRET规律，并在石墨烯-铒体系中区分耗散衰变与色散耦合。
AI 中文摘要
我们建立了一套量子电动力学理论，用于在不依赖具体材料的导体-介质-导体异质结构中实现自发辐射与Förster共振能量转移（FRET）的通用调控。该平台由厚度为$W$的介质间隔层构成，其两侧为两个栅极可调的二维导体。周围材料仅需提供的微观输入是两个导电层的横磁与横电反射振幅$r_{\text{TM/TE}}(q_ρ,ω)$。我们从QED光子传播子出发，推导了相同几何结构下的推迟麦克斯韦并矢、真空/哈达玛场传播子以及时序费曼传播子。自发辐射速率由局域真空谱密度调控，而FRET则由非局域的推迟/超前乘积$\tilde{\text{G}}_{\text{R}}(\boldsymbol{x}_D,\boldsymbol{x}_A;ω_D)\tilde{\text{Im}}\boldsymbol{\tilde{α}}_A(ω_D)\tilde{\text{G}}_{\text{A}}(\boldsymbol{x}_A,\boldsymbol{x}_D;ω_D)$调控。在透明极限$r_{\text{TM}}\to 0$下，近场FRET速率恢复为体材料的$x_ρ^{-6}$规律。在Dirichlet/理想电导体（PEC）分支$r_{\text{TM}}\to -1$下，无禁带横模被消除，给体-受体耦合呈现贝塞尔$K$函数包络，在大横向间距下产生指数屏蔽的FRET速率$Γ_{D\to A}\times\tilde{\text{exp}}(-2πx_ρ/W)$。在相反的类Neumann/理想磁导体（PMC）分支$r_{\text{TM}}\to 1^-$下，近无禁带的横模得以保留，产生宽范围的准二维对数传播子，在栅极可编程的范围$x_{ρ,*}\tilde{\times} W/(1-r_{\text{TM}})$内增强非局域电磁耦合。对于石墨烯-铒（Er）实现方案，同一个推迟格林张量还可将受其吸收部分调控的耗散性在壳Er到石墨烯的衰变，与受其虚部调控的色散性虚等离激元介导的Er-Er耦合区分开来；等离激元带隙可抑制前者同时保留后者。
英文摘要
We develop a quantum-electrodynamical theory for universal tuning of spontaneous emission and Förster resonance energy transfer (FRET) in a material-agnostic conductor-dielectric-conductor heterostructure. The platform consists of a dielectric spacer of thickness $W$ bounded by two gate-tunable two-dimensional conductors. The only microscopic input from the surrounding materials is the transverse-magnetic and transverse-electric reflection amplitudes $r_{\TM/\TE}(q_ρ,ω)$ of the two sheets. Starting from the QED photon propagator, we derive the retarded Maxwell dyadic, the vacuum/Hadamard field propagator, and the time-ordered Feynman propagator in the same geometry. The spontaneous-emission rate is controlled by the local vacuum spectral density, while FRET is controlled by the nonlocal retarded/advanced product $\obG_{\text R}(\bx_D,\bx_A;ω_D)\Im\,\balpha_A(ω_D)\obG_{\text A}(\bx_A,\bx_D;ω_D)$. In the transparent limit $r_{\TM}\to 0$, the near-field FRET rate recovers the bulk $x_ρ^{-6}$ law. In the Dirichlet/PEC branch $r_{\TM}\to -1$, the gapless transverse mode is removed and the donor-acceptor coupling acquires a Bessel-$K$ envelope, giving an exponentially screened FRET rate $Γ_{D\to A}\propto\exp(-2πx_ρ/W)$ at large lateral separation. In the opposite Neumann/PMC-like branch $r_{\TM}\to 1^{-}$, a nearly gapless transverse mode survives and produces a wide quasi-two-dimensional logarithmic propagator, enhancing the nonlocal electromagnetic coupling over a gate-programmable range $x_{ρ,*}\sim W/(1-r_{\TM})$. For graphene-Er implementations, the same retarded Green tensor also separates dissipative on-shell Er-to-graphene decay, governed by its absorptive part, from dispersive virtual-plasmon-mediated Er-Er coupling, governed by its reactive part; a plasmonic band gap can suppress the former while retaining the latter.
Comments27 pages, 11 figures
