Entangled Atom Pair Quantum Processor

Entanglement is the main feature of quantum mechanics that makes it distinct from classical physics. The generation, manipulation, and detection of entanglement are the essential components of quantum research. Due to the great significance, the Nobel Prize in Physics 2022 was awarded to scientists for entanglement experiments and pioneering quantum science and technologies. As an emerging field of physics and engineering, quantum technology experienced explosive development in the last two decades. Among numerous physical platforms, neutral atom devices exhibit many unique features in the aspects of diverse configurations, high scalability, long coherence time, high degree of control, and deterministic detection. Many advanced quantum technologies based on atoms are desiderated for solving scientific problems and developing quantum applications. This project aims to develop an atom optics platform to implement quantum entanglement techniques with the advantages of ultracold atoms. The dissociation of a diatomic molecule creates nonlocal entanglement between two fermions in a pair. This process constitutes a deterministic entanglement source, and the atoms can be addressed, manipulated, and detected individually with ultra-high fidelity. The guided atomic matter waves in tailored potentials constitute a versatile platform to replicate successful elements. In the long term, we envision developing a fully programmable atom-optics processor and integrating it into robust, large, complex atomtronics devices. The platform will be built based on the Lithium-6 ultracold quantum gas experiment in Atominstitut, TU Wien. Experiments will be conducted in multiple 1D optical waveguides parallelly arranged in a single layer. A trapping site at the center of each waveguide will be initialized with a single 6 Li2 molecule, and the subsequent molecular dissociation creates entanglement between two emerging atoms launched into waveguides. Tens to hundreds of parallel waveguides allow us to scale up the number of qubits. We will employ radio-frequency pulses to flip the target atoms addressed by selectively shifting their resonance frequencies with tailored focused laser beams. Two qubit states will be individually probed in situ at single-atom sensitivity. A successful demonstration of this research will enable a novel atom optics quantum processor similar to the photonic quantum information processors but mitigates their disadvantages. This will allow building a new, atom-optical platform into the quantum information community and provide new opportunities ranging from experiments for fundamental quantum physics to developing quantum technologies.

This project develops a new way to create and control pairs of quantum particles-individual atoms-that are strongly linked to each other, even when they are far apart. Such "entangled" atoms are a key resource for future quantum technologies, including quantum computing, quantum information processing and precise sensors. Our main achievement is the design of an integrated platform that can reliably produce these entangled atom pairs on demand. The approach starts from single molecules made of two atoms cooled to extremely low temperatures. By carefully breaking these molecules apart, we generate two atoms that naturally share a deep quantum connection. Because of the fundamental laws of physics, this process produces entanglement in a highly controlled and predictable way. Each atom can then be individually addressed, manipulated, and measured with very high precision. Using advanced imaging techniques, we can detect single atoms and determine their quantum state with better than 99% accuracy. This allows us not only to create entanglement, but also to verify and use it reliably. A key advantage of this platform is its scalability. The system can be extended to many parallel channels, allowing the simultaneous creation and control of hundreds of entangled atom pairs. This overcomes one of the major challenges in quantum technology: how to efficiently prepare large numbers of quantum bits (qubits) in a well-defined state. Beyond demonstrating a new experimental capability, this work opens the door to a wide range of applications. The platform can be used to test fundamental questions about quantum mechanics, such as how nonlocal correlations arise between distant particles. It also provides a promising route toward building quantum processors based on atoms, offering an alternative to existing approaches based on photons. In the longer term, the technology could contribute to advances in quantum computing, secure communication, and precision measurement. By integrating key components into compact and scalable devices, this work helps bring quantum technologies closer to practical applications.