Preparation of non-classical photon states in laser-driven quantum-dot-cavity systems under the influence of acoustic phonons

声声子影响下激光驱动量子点腔系统中非经典光子态的制备

• 批准号: 419036043
• 负责人: Professor Dr. Vollrath Martin Axt
• 金额: --
• 依托单位: Lehrstuhl für Theoretische Physik III (Quantentheorie der kondensierten Materie)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/419036043?language=en
• 关键词: Preparation; non; classical; photon; states

In this project we shall explore theoretically possibilities to prepare non-classical photon states, such as, e.g., Schrödinger-cat states, Fock states or polarization entangled two-pair states, in quantum-dot-cavity systems. Such states can not only be used to test the basics of quantum mechanics but also serve as central building blocks for possible applications in photonics, quantum-information-processing and quantum-cryptography.We shall investigate in how far the photon state in a quantum-dot-cavity system can be manipulated by different laser excitations. Of particular interest are the new physical effects evoked by the interaction with lattice oscillations (phonons) which cannot be avoided in semiconductor based quantum dot systems. Phonons may be an obstacle for the preparation; but it is also possible that phonon-assisted processes may enable new preparation protocols.We shall also study how far the generation of photon-pairs, which arise from the decay of a biexciton (i.e. a state with two electron-hole pairs) in the resonator, can be influenced by external laser fields and what role phonons play in this case. Also the so far unexplored possibility to switch between different types of entanglement will be investigated.Two-time correlation functions shall be evaluated avoiding the usually invoked quantum regression theorem which is not valid for systems with a non-Markovian environment (here provided by the phonons). Two-time correlation functions are directly connected to measurable quantities and contain important information about the non-classical properties of photons. New physical insights in particular into the significance of non-Markovian effects are expected to be found by simulating key quantities of photonic systems such as the indistinguishability, the coherence, the degree of entanglement as well as by recording the photon statistics of N-photon bundles.All calculations within this project will be performed using numerically complete path-integral methods without any approximation to the usually used models. For the quantum-dissipative multi-level systems studied here, such a complete treatment has become available only recently due to a methodological progress reached by the group of the applicant. First studies reveal that even advanced well established approximate methods lead to large deviations from the numerically complete results in praxis-relevant parameter ranges. The errors are particularly large for photonic properties, which are the focus oft the present project. Thus, the numerically complete treatment is decisive for reaching conclusive results.

在这个项目中，我们将探索在量子点腔系统中制备非经典光子态的理论上的可能性，例如薛定谔猫态、福克态或偏振纠缠两对态。用于测试量子力学的基础知识，但也可作为光子学、量子信息处理和量子密码学中可能应用的中心构建块。我们将研究光子状态在多远的距离量子点腔系统可以通过不同的激光激发来操纵，特别令人感兴趣的是与晶格振荡（声子）相互作用引起的新物理效应，这在基于半导体的量子点系统中是不可避免的。制备；但声子辅助过程也有可能实现新的制备方案。我们还将研究双激子衰变产生的光子对的产生程度谐振器中的（即具有两个电子空穴对的状态）可能会受到外部激光场的影响，以及声子在这种情况下扮演什么角色。此外，还将研究迄今为止尚未探索的在不同类型的纠缠之间切换的可能性。时间相关函数的评估应避免通常调用的量子回归定理，该定理对于具有非马尔可夫环境的系统无效（此处由声子提供），两次相关函数直接与可测量的量相关并包含。关于光子非经典特性的重要信息，特别是对非马尔可夫效应的重要性的新物理见解，预计将通过模拟光子系统的关键量（例如不可区分性、相干性、纠缠度）来发现。例如通过记录 N 光子束的光子统计数据。该项目中的所有计算都将使用数值完整的路径积分方法进行，而不对通常使用的模型进行任何近似。在这里研究的量子耗散多级系统，由于申请人小组在方法论上取得的进展，这种完整的处理方法最近才成为可能，首次研究表明，即使是先进的完善的近似方法也会导致与数值完整的较大偏差。导致与实践相关的参数范围的误差特别大，这是本项目的重点，因此，数值完整的处理对于得出结论性结果至关重要。