Analog Quantum Simulations in Arrays of Surface Ion Traps (AQUAS)

• Applicant: Professor Dr. Tobias Schätz
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2013 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 237456450

Numerical simulations of some tens of interacting quantum particles are intractable, even on supercomputers. That is, we can not translate efficiently quantum behaviour arising with superposition states or entanglement into the classical language of conventional computers. However, we could gain deeper insight into complex quantum dynamics via experimentally simulating the quantum behaviour of interest in another quantum system, where the relevant parameters and interactions can be controlled and observables of interest detected sufficiently well. In 2007, we performed the prove-of-principle experiment for the class of quantum spin systems with trapped ions, by simulating the transition of a quantum magnet from paramagnetic into entangled ferromagnetic order.However, it is well known, that the dynamics of one-dimensional systems can still get described very accurately by numerical approximations. This does not hold for higher-dimensional systems, which remain an intriguing domain for Quantum Simulators. We were already capable to establish a new class of Quantum Simulations therein.In the year 2015 we demonstrated that nano- and micro-fabrication technology enables us to build up a two-dimensional array of individually trapped and controlled ions. Indeed, we started with three ions forming a triangle only. However, this basic cell fulfils all specifications already to get exploited as a two-dimensional Quantum Simulator, such as, individual control of the electronic and motional degrees of freedom on the level of single quanta; and it is yielding an ion trap architecture that is scalable. Here, we propose combining the experiences gained in theory and experiment to run paradigmatic Quantum Simulations, allowing us to further improve and scale our approach. The results will enable us to design larger experimental quantum simulations of idealized or open systems. We aim at exploring the prospects of enlarged quantum simulations and the question, for which purposes a quantum simulator based on trapped ions can efficiently contribute. A comparatively small amount of simulation-ions (tens in two-dimensions, considering and exploiting their quantized motion) is predicted to permit addressing problems of interest, outperforming any future classical computer and permitting to gain deeper insight into complex quantum behaviour.

• DFG Programme: Research Grants