New Perspectives in Strongly Interacting Systems: preparing for quantum gauge simulators.

• Applicant: Dr. Debasish Banerjee
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 392051989

A first-principles study of the non-perturbative physics in strongly interacting systems is a challenging field of research. It impacts a wide variety of areas, from new physics beyond the Standard Model of particle physics, to Quantum Chromodynamics (QCD), and even to astrophysical objects, such as neutron stars. Development of new algorithms based on the better understanding of the system helps in improved applicability of Monte Carlo methods. Even so, many interesting problems, particularly that of real-time evolution, are beyond the scope of present numerical techniques, and need new methods to make progress. The existing tools still play a crucial role in order to benchmark the new methods. Quantum simulation is a new method, which has rapidly developed in the past two decades. Quantum simulators are special purpose quantum computers to emulate specific physical systems, realized with cold atoms in optical lattices or ions trapped in ion traps. Once they work, they will by far outperform their classical counterparts for certain problems. Several such examples already exist in condensed matter physics and are being increasingly developed for particle physics applications. Together with existing theoretical and Monte Carlo methods, they have a great potential for increasing our understanding of strongly correlated systems. This project will consider some quantum simulators relevant for QCD-related physics. Certain lattice gauge theories (called quantum link models) with finite dimensional Hilbert spaces are ideal candidates to be implmented in optical lattices. The research will focus on the quantum simulation of the considered models, together with the development of classical simulation algorithmsfor benchmarking these quantum simulators, particularly using the static properties. The study of dynamical properties, like real-time evolution, can then be studied with quantum simulators. Realization of these models in the laboratories are only approximate. The classical algorithms developed will account for this. Additionally, this project will study whether continuum field theories can be realized with the quantum link models. This has crucial impact on the progress of quantum simulators for continuum gauge theories. Moreover, the same classical simulation algorithms can address some aspects of conformal field theories in dimensions d > 2. This can provide an independent check of new numerical and analytical methods (such as the conformal bootstrap). The excellent local scientific environment at the Humboldt University and DESY Zeuthen, and close contacts of the PI with atomic physicists in Univeristy of Innsbruck, Austria are expected to contribute to the success of the proposed project and make a significant impact on the aforementioned fields.

• DFG Programme: Research Grants