AI 中文总结
本研究提出一种数值精确的矩阵乘积态（MPS）方法，模拟波导中少光子压缩脉冲与二能级发射体的相互作用，揭示其特有量子关联与非线性动力学，无需马尔可夫和玻恩近似且可扩展至多发射体系统。
AI 中文摘要
压缩光态在量子光学中占据特殊地位，在新兴量子技术中具有潜在的深远应用。我们提出了一种数值精确的矩阵乘积态（Matrix Product States，MPS）方法，用于模拟波导环境中少光子水平的压缩光量子脉冲与二能级系统的相互作用。我们将压缩态表示为Fock态的相干叠加，并探究由此产生的非线性布居动力学以及多光子关联函数。我们展示了压缩脉冲如何产生仅为压缩脉冲所特有的量子关联，包括透射场的$\boldsymbol{\rangle b(t) b(t+t')\boldsymbol{\neg}$以及$\boldsymbol{\rangle b^\u2020(t) b^\u2020(t+t') b(t+t') b(t) \boldsymbol{\neg}$。我们还证明了一阶关联函数$\boldsymbol{\rangle b(t) b(t+t') \boldsymbol{\neg}$展现出的非线性光子关联，与已知且已测量的双光子散射态的关联相似。最后，我们还研究了脉冲与二能级系统相互作用前后的压缩光谱，并强调了入射脉冲光谱带宽的作用。该MPS理论能够对任意带宽的压缩进行建模，无需对光-物质相互作用过程做任何马尔可夫近似和玻恩近似，并且可以轻松扩展到具有多个发射体和时滞反馈的波导系统。
英文摘要
Squeezed light states have a special place in quantum optics with potentially profound applications in emerging quantum technologies. We present a numerically-exact matrix product states (MPS) approach to model quantum pulses of squeezed light, at the few-photon level, interacting with a two-level system in a waveguide environment. We represent the squeezed state as a coherent superposition of Fock states and explore the nonlinear population dynamics as well as multi-photon correlation functions that emerge. We show how the squeezed pulse can create quantum correlations that are unique to squeezed pulses, including $\langle b(t) b(t+t')\rangle$ for transmitted fields as well as $\langle b^\dagger(t) b^\dagger(t+t') b(t+t') b(t) \rangle$. We also demonstrate how $\langle b(t) b(t+t') \rangle$, a first-order correlation function, shows nonlinear photon correlations that are similar to those known and measured for two-photon scattering states. Finally, we also study the squeezed spectra of the pulse before and after interacting with the two-level system, and highlight the role of the spectral bandwidth of the incident pulse. The MPS theory allows the modeling of arbitrary bandwidth squeezing without making any Markov and Born approximations for the light-matter interaction processes, and can easily be extended to waveguide systems with multiple emitters and time-delayed feedback.
Comments13 pages, 9 figures
