Dynamic control of resonance fluorescence in graphene quantum plasmonics

TL;DR

This work analyzes resonance fluorescence from a driven two-level emitter in the vicinity of a graphene sheet, deriving an exact closed-form expression for the graphene-mediated SP field that remains valid in near and far regions. It computes graphene-enhanced decay rates and shows strong, tunable modifications to the fluorescence spectrum and coherence via the graphene gating parameter $E_F$, enabling dynamic control of the Mollow triplet and antibunching. The results highlight extreme field confinement, large Purcell enhancements, and rich parameter dependence on distance and dipole orientation, with clear implications for integrated quantum photonics. The methodology provides a framework for tailoring light-mmatter interactions in graphene-based plasmonic environments.

Abstract

The spectral and statistical properties are explored for surface plasmon (SP) emission in resonance fluorescence from a driven two level emitter in the proximity of 2D single graphene sheet. We derive an exact closed form analytic expression for the emitted SP field valid in the near and far regions. The SP field profile and spectrum function depend on the graphene conductivity and take into account the dynamic control parameters, namely Fermi energy. We present analysis for the spectrum and second order coherence functions and discuss the possibility of their control using graphene system parameters to manipulate the spectral linewidth and second order coherence function.

Figures (7)

• Figure 1: 2D single graphene sheet of conductivity $\sigma(\omega)$ between two semi-infinite half spaces with constant dielectric functions $\varepsilon_1$ and $\varepsilon_2$. A two level emitter is placed above graphene sheet in upper medium.
• Figure 2: Real and imaginary parts of graphene plasmonics complex wave number as functions of mode energy for TM modes (a,b) and TE modes (c). In (a,b) the solid upper blue line shows $k_{||}=\text{Re}[K_{||}]$ for $\varepsilon_1=1,\varepsilon_2=2$, while solid lower red line gives $\varepsilon_1= \varepsilon_2=1$ case. The lower dotted lines are the corresponding imaginary parts. Fermi energy $E_F=0.5$ eV (a) and $E_F=1$ eV (b). The inset in (a) shows the group velocity $v_g/c$ for both TE (upper red line) and TM ( lower blue line). The inst in (b) shows zoom in portion which displays losses at low frequency. In (c) the solid upper red line shows $k_{||}=\text{Re}[K_{||}]$ for $\varepsilon_1=1,\varepsilon_2=2$ case, while the solid lower blue line is for the $\varepsilon_1= \varepsilon_2=1$ case. The lower dotted lines are the corresponding imaginary parts. The inset in (c) shows an extended energy scale.
• Figure 3: (a) The SP Purcell enhancement factor $P_F=\Gamma_{sp}/\Gamma_0$ as a function of atomic transition frequency $\hbar\omega_0$ (eV) for dipole emitter placed $10$ nm (black solid line), $20$ nm (blue dashed line) and $30$ nm (red dotted line), for symmetric geometry $\varepsilon_1=\varepsilon_2=1$, $E_F=0.5$ eV and $\Omega=1.5\Gamma$. (b) The enhancement factor for different Fermi energies ; $E_F=0.5$ eV (black solid line), $E_F=1$ eV (blue dashed line), and $E_F=1.5$ eV (red dotted line) for $z=20$ nm, and $\Omega=1.5\Gamma$.
• Figure 4: The field profile function $|E|$ as a function of separation $R_{||}$ nm for (a) different graphene-emitter separations $z=5$ nm brown solid line, $z=10$ nm dotted red line and $z=20$ nm dashed blue line. (b) different dipole emitter orientations $\theta_d=\pi/10$ ( upper blue dashed line), $\theta_d=\pi/2$ ( brown solid line), and $\theta_d=0.9\pi$ ( red dotted line), $\phi=\pi/4$. These figures show oscillatory behavior of field profile indicating strong SP-atom interaction.
• Figure 5: (a). The spectrum function as a function of atomic transition frequency $\omega_0$ in free space for Rabi frequency $\Omega=0.2\Gamma_0$ (red dashed line), $\Omega=1\Gamma_0$ (black dotted line) and $\Omega=1.5\Gamma_0$ (blue solid line). (b) The spectrum for an atom near the graphene sheet $z=20$ nm (blue solid), $z=35$ nm (red dotted), $z=50$ nm (black dashed), for Rabi frequency $\Omega=1.5 \Gamma$. (c) The spectrum for an atom $z=20$nm above the graphene sheet and Rabi frequency $\Omega=1.5\Gamma$ for different Fermi energy $E_F=0.5$ eV (black solid line) ; $E_F=1$ eV (blue dashed line), and $E_F=1.5$ eV (red dotted line) .