Neutral-atom quantum systems with high connectivity

Many important processes in nature are too complex to be fully described by classical computers. For example, the computational effort required for a quantum-mechanical description of novel materials or chemical reactions grows exponentially with the number of particles involved, meaning that even the most powerful supercomputers quickly reach their limits. With the help of so-called quantum simulators, it may be possible to overcome this limitation in the future and thus investigate phenomena that are difficult or even impossible for classical computers to access. On the path toward such applications, ultracold atoms and molecules play a central and highly promising role: in current experiments, they can already be individually and precisely manipulated at extremely low temperatures. This makes it possible to prepare single particles so that they obey the same quantum-mechanical rules as the problem under investigation. To fully exploit this enormous potential for simulating complex problems, however, it will be necessary in the future to achieve a high degree of connectivity and quantum entanglement among many particles, covering large distances between them. This is precisely the goal of the Special Research Area (SFB) Qnnect, in which scientists from theory and experiment work together in an interdisciplinary research program at the interfaces of atomic physics, quantum optics, and many-body theory. The shared objective of a total of eight research groups from TU Wien, the University of Vienna, ISTA, the University of Innsbruck, IQOQI Innsbruck (ÖAW), and LMU Munich is to lay the foundation for the next generation of quantum simulators. To this end, specifically suited atoms and molecules are trapped in synthetic lattice structures formed by laser light, assembled into large architectures, and quantum-mechanically interconnected by exploiting their long-range interactions. Through the realization and investigation of such quantum systems, which are now becoming experimentally accessible for the first time, the planned collaboration promises not only a deeper understanding of novel states of matter, but also practical breakthroughs in the field of quantum technology.