[论文解读] Higher-order spatial photon interference versus dipole blockade effect

Arthur Rotari, Mihai Macovei|arXiv (Cornell University)|Feb 20, 2026

Quantum Information and Cryptography被引用 0

一句话总结

Paper analyzes steady-state dynamics of three dipole-dipole coupled two-level emitters in an equilateral triangle, showing sub-Poissonian photon streams and higher-order spatial interference from the thermal reservoir, largely independent of dipole blockade.

ABSTRACT

The steady-state quantum dynamics of three dipole-dipole coupled two-level emitters, fixed at the vertices of an equilateral triangle, and interacting via the environmental thermostat is investigated. We have analytically obtained the populations of the involved three-atom cooperative states as well as of the second- and third-order spatial photon correlation functions of the light scattered by the few-qubit sample. As a consequence, we have demonstrated that this incoherently excited system spontaneously generates streams of single photons possessing sub-Poissonian photon statistics. In analogy to the dipole-dipole blockade, one may expect that at smaller inter particle distances, compared to the photon emission wavelength, the reported phenomenon has the same origin. However, we have shown that the quantum photon features are due to the interaction's nature of the few symmetrically arranged two-level emitters with the surrounding thermal reservoir. Respectively, at larger atomic intervals the effect occurs because of high-order spatial interference phenomena. Sub-wavelength interference fringes can be observed too, via measurements of spatial higher-order photon correlation functions.

研究动机与目标

• Motivate quantum light generation with non-classical statistics in a small emitter ensemble.
• Investigate how incoherent excitation by a thermal reservoir drives steady-state populations of cooperative states.
• Compute second- and third-order spatial photon correlation functions to reveal interference in thermally driven systems.

提出的方法

• Model a three-atom system fixed at the vertices of an equilateral triangle interacting with a thermal electromagnetic reservoir.
• Derive and use a master equation including dipole-dipole interactions and collective decay terms.
• express the system in terms of Dicke-like cooperative states and obtain steady-state populations (expressions (13) and (14)).
• Define and evaluate spatially dependent G1, G2, G3 and their normalized forms g(2) and g(3) as in (15)-(19).
• Analyze the role of chi (collective coupling) and delta (dipole-dipole shift) on steady-state dynamics and photon statistics.

Figure 1: Schematic picture of the considered system. Three atoms, $j\in\{1,2,3\}$ , are arranged to form an equilateral triangle. Detectors $D_{k}$ , placed at ${\bf R_{k}}$ , $k\in\{1,2,3\}$ , detect the spontaneously scattered photons by the atomic sample. Respectively, ${\bf r_{jl}}$ are the int

实验结果

研究问题

• RQ1 Under thermal excitation, what are the steady-state populations of the symmetric and antisymmetric three-atom cooperative states?
• RQ2 在这个三发射体几何中，高阶空间光子相关性是否表现出亚波长干涉？
• RQ3 是由Dicke样态协同动力学还是发射体-热浴相互作用导致的亚泊松光子统计，以及它与偶极阻塞之间的关系如何？
• RQ4 二阶和三阶空间光子相关函数如何依赖探测器几何和原子间距？

主要发现

• 稳态人口由表达式(13)在χ ≠ 1时和表达式(14)在χ = 1时给出，显示在某些条件下人口在协同态之间的分布与χ和δ无关。
• 在Dicke极限（χ → 1）中，仅对称态参与，反对称态解耦，给出明确的稳态形式。
• 给出二阶和三阶空间光子相关性G2和G3，得到g^(2)(0)和g^(3)(0)，揭示亚泊松统计和潜在的亚波长干涉模式。
• 本文表明在该设定中的亚泊松光子统计源于原子-热浴相互作用和高阶空间干涉，而不仅仅是偶极-偶极阻塞。
• 对于某些探测器构型，g^(2)(0)在4/9与4/3之间，表明几何排列（如r和探测角）可调的量子统计行为。
• 当两个探测器对称放置时，高阶空间相关性可观测亚波长干涉条纹。

Figure 2: The energy diagram of a spatially equidistant three-atom sample. The anti-symmetrical states $\{|6\rangle,|7\rangle\}$ and $\{|3\rangle,|4\rangle\}$ are shifted by the dipole-dipole coupling strength among the emitters, i.e. $+\delta$ , whereas the symmetrical states $\{|5\rangle,|2\rangle