We report on the development of a modular platform for programmable quantum simulation with atomic quantum gases. The platform is centered around exchangeable optical modules with versatile functionalities. The performance of each module is disentangled from all others, enabling individual validation and maintenance of its outputs. The relative spatial positioning of the modules with respect to the position of the atomic sample is set by a global reference frame. In this way, the platform simplifies reconfiguration and upgrading of existing setups and accelerates the design of new machines in a time- and cost-efficient manner. Furthermore, it facilitates collaborations between different experimental groups. This standardized hardware design framework, which we call Heidelberg Quantum Architecture, paves the way towards a new generation of on-demand and highly adaptable quantum simulation experiments.
We report on the development of a modular platform for programmable quantum simulation with atomic quantum gases. The platform is centered around exchangeable optical modules with versatile functionalities. The performance of each module is disentangled from all others, enabling individual validation and maintenance of its outputs. The relative spatial positioning of the modules with respect to the position of the atomic sample is set by a global reference frame. In this way, the platform simplifies reconfiguration and upgrading of existing setups and accelerates the design of new machines in a time- and cost-efficient manner. Furthermore, it facilitates collaborations between different experimental groups. This standardized hardware design framework, which we call Heidelberg Quantum Architecture, paves the way towards a new generation of on-demand and highly adaptable quantum simulation experiments.
The presented thesis reports on the development of a broadly applicable, open-source, modular system architecture for quantum gas experiments, which has been named Heidelberg Quantum Architecture (HQA). In the ongoing rollover of quantum gas apparatuses from mere experiments to usable platforms for quantum simulation, similar to classical computing in the 1950s, such an architecture can be beneficial in the pursuit of improving the usability and raising the technology readiness level (TRL) of these systems. An exemplary quantum gas apparatus for quantum simulation with ultracold 6 Li, follow- ing the guidelines of HQA, is constructed. It is named Heidelberg Quantum Architecture based experiment described in this thesis (HQA-ONE). The modular concept of Heidel- berg Quantum Architecture (HQA), which disentangles the complexity of the quantum gas apparatus into subsystems that are attached to a common mechanical frame of reference (FOR), is demonstrated. A passive interfacing precision of the exchangeable modules mounted to the framework of around ±10µm is measured. The reconfigurable apparatus HQA-ONE is equipped with modules for deterministic preparation of atom number states in the ground state of an optical tweezer to exemplarily demonstrate a core capability of quantum simulators, quantum state initialization, with the apparatus and indirectly with the platform. Further modules to choose from when configuring the apparatus for quantum simulations in the future are developed, constructed, and presented in the thesis, underlining the reconfiguration character of the platform and its versatility.
Quantum simulators are a promising technology on the spectrum of quantum devices from specialized quantum experiments to universal quantum computers. These quantum devices utilize entanglement and many-particle behaviors to explore and solve hard scientific, engineering, and computational problems. Rapid development over the last two decades has produced more than 300 quantum simulators in operation worldwide using a wide variety of experimental platforms. Recent advances in several physical architectures promise a golden age of quantum simulators ranging from highly optimized special purpose simulators to flexible programmable devices. These developments have enabled a convergence of ideas drawn from fundamental physics, computer science, and device engineering. They have strong potential to address problems of societal importance, ranging from understanding vital chemical processes, to enabling the design of new materials with enhanced performance, to solving complex computational problems. It is the position of the community, as represented by participants of the NSF workshop on "Programmable Quantum Simulators," that investment in a national quantum simulator program is a high priority in order to accelerate the progress in this field and to result in the first practical applications of quantum machines. Such a program should address two areas of emphasis: (1) support for creating quantum simulator prototypes usable by the broader scientific community, complementary to the present universal quantum computer effort in industry; and (2) support for fundamental research carried out by a blend of multi-investigator, multi-disciplinary collaborations with resources for quantum simulator software, hardware, and education.
In this thesis, we present the first experimental results obtained from a newly developed modular quantum gas platform. The platform features exchangeable optical modules that can be individually characterized and maintained, enabling rapid reconfiguration with modules of diverse functionality. We configure the platform to carry out first quantum simulation experiments using fermionic Li-6 in optical tweezers. In particular, we realize motional ground-state systems in a one-dimensional optical tweezer, demonstrate the preparation of spin-imbalanced systems, explore scaling to multiple tweezers, and extend the system to a tunnel-coupled double well, realizing experimental cycle times as short as 800 ms. We further present the development of a novel free-space fluorescence imaging technique, which utilizes the polarization degree of freedom of the emitted photons to encode spin information. This method extends established free-space fluorescence imaging methods both conceptually and technically, and facilitates their application across a broad range of quantum gas experiments. Finally, we report on the first realization of optical shielding in Li-6, with observed light shifts on the GHz scale. We find that, due to the internal structure of Li-6, theoretical descriptions used for other systems are no longer sufficient to describe such light shifts. We therefore develop a novel theoretical model based on the numerical diagonalization of the strongly coupled multilevel Hamiltonian describing states in the 2p_1/2 , 2p_3/2 , and 3s_1/2 manifolds of Li-6. This model allows for a quantitative description of state-dependent light shifts and provides a foundation for the precise engineering of energy levels. We utilize the differential light shift to achieve high-fidelity shielding of quantum ground state systems from imaging, thereby demonstrating the ability to locally address and measure cold atomic quantum systems of Li-6. This capability for local control and measurement enables the implementation of a broad range of quantum simulation experiments.
The realization of a Quantum Internet is expected to transform communication networks by enabling intrinsically secure information exchange and distributed quantum applications. However, the experimental study of large-scale quantum networks remains limited by the high cost and operational constraints of quantum hardware. To address this challenge, this paper presents the design of a platform conceived to support research and experimentation in the field of quantum networking. The proposed system provides an emulation environment that mirrors the behavior of a real quantum network, enabling researchers to test protocols and mechanisms through a set of quantum operation instructions accessible via an Application Programming Interface (API). Emulated quantum nodes can be deployed across physically distributed locations, using physical or virtual machines or virtualization containers, allowing experiments to reproduce realistic network conditions and inter-node interactions. This approach enables applications to be executed over a persistent, configurable, and interactive environment that integrates both quantum and classical communication layers. To validate the feasibility of the proposed design, a prototype has been built and used to demonstrate its operation through a multi-hop quantum teleportation proof of concept. The results confirm the viability and flexibility of the architecture, laying the foundation for a distributed framework that facilitates the development and evaluation of quantum network architectures, control mechanisms, and experimental use cases.
As quantum networking hardware remains costly and not yet widely accessible, simulation tools are essential for the design and evaluation of quantum network architectures and protocols. However, designing a scalable and computationally efficient quantum network simulator is intrinsically challenging: i) quantum dynamics must be emulated on classical computing platforms while capturing the stateful and non-local nature of entanglement, a quantum resource without any classical networking analog; ii) quantum networking is inherently hybrid, as protocol execution also fundamentally depends on classical signaling. This makes a tight and faithful co-simulation of quantum operations and classical message exchanges a core requirement. In this light, we present Q2NS, a modular and extensible quantum network simulator, built on top of ns-3, designed to seamlessly integrate quantum-network primitives with ns-3's established classical protocol stack. Q2NS adopts a modular architecture that decouples protocol control logic from node- and channel-level operations, enabling rapid prototyping and adaptation across heterogeneous and evolving Quantum Internet scenarios. Q2NS natively supports multiple quantum state representations through a unified interface, allowing interchangeable state-vector, density-matrix, and stabilizer backends. We validate Q2NS through realistic use-case studies and comprehensive benchmarks, demonstrating superior computational efficiency over representative state-of-the-art alternatives, while preserving modeling flexibility. Finally, we provide a dedicated visualization tool that jointly captures physical and entanglement-enabled connectivity and supports entangled-state manipulations, facilitating an intuitive interpretation of entanglement dynamics and protocol behavior. Q2NS offers a flexible, open, and scalable simulation platform for advancing Quantum Internet research.
Quantum network simulators are essential for the design and evaluation of quantum network architectures and protocols. However, developing an effective simulator is particularly challenging due to the stateful and non-local nature of quantum entanglement, which requires persistent state awareness and tight in-network coordination. Moreover, because quantum communication protocols inherently rely on classical signaling, a realistic simulator must seamlessly integrate classical and quantum communication primitives within a unified framework. In this work, we presentQ2NS, a modular and extensible quantum network simulation framework built on top of ns-3. The architectural design ofQ2NSenforces a clear separation of concerns between the operational functionalities of modules and entities and the overarching control logic, enabling easy adaptation to heterogeneous and rapidly evolving Quantum Internet paradigms while leveraging ns-3's mature classical networking stack. Additionally,Q2NSincludes a dedicated visualization tool to facilitate developing an intuitive understanding of entanglement-based quantum networking. This design enables accurate modeling of entanglement dynamics and protocol control logic, by providing a flexible, open, and scalable platform for advancing the Quantum Internet research.