Freiburg 2024 – scientific programme
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A: Fachverband Atomphysik
A 5: Ultra-cold Plasmas and Rydberg Systems I (joint session A/Q)
A 5.1: Talk
Monday, March 11, 2024, 17:00–17:15, HS 1010
Time-reversal in a quantum many-body spin system — •Sebastian Geier1, Adrian Braemer1,2, Eduard Braun1, Maximilian Müllenbach1, Titus Franz1, Martin Gärttner1,2,3, Gerhard Zürn1, and Matthias Weidemüller1 — 1Physikalisches Institut, Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany — 2Physikalisches Institut, Im Neuenheimer Feld 226 — 3Institute of Condensed Matter Theory and Optics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, 07743 Jena, Germany
Time reversal in a macroscopic system is contradicting daily experience. Yet, with the precise control capabilities provided by modern quantum technology, the unitary evolution of a quantum system can be reversed, rendering it a powerful tool for scientific discovery and technological advancements. Here, we implement a time-reversal protocol in a dipolar interacting many-body spin system represented by Rydberg states in an atomic gas. By changing the states encoding the spin, we flip the sign of the interaction Hamiltonian, and demonstrate the reversal of the relaxation dynamics of the magnetization by letting a demagnetized many-body state evolve back-in-time into a magnetized state. We elucidate the role of atomic motion using the concept of a Loschmidt echo. Finally, by combining the approach with Floquet engineering, we demonstrate time reversal for a large family of spin models with different symmetries. Our method of state transfer is applicable across a wide range of quantum simulation platforms and has applications far beyond quantum many-body physics.
Keywords: Quantum simulation; Many-body systems; Rydberg atoms; Time reversal; Spin systems