Ergodic dynamics and thermalization in an isolated quantum system
| Autor: | Josh Mutus, Michael Fang, Andrew Dunsworth, Anthony Megrant, Anatoli Polkovnikov, Rami Barends, Pedram Roushan, Charles Neill, Yu Chen, Michael Kolodrubetz, Chris Quintana, Benjamin Chiaro, Ted White, John M. Martinis, Daniel Sank, Zijun Chen, Brooks Campbell, James Wenner, Peter O'Malley, Amit Vainsencher, Evan Jeffrey, Julian Kelly |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Physics
Quantum Physics Quantum discord Fluids & Plasmas Quantum dynamics FOS: Physical sciences General Physics and Astronomy Ergodic hypothesis Stationary ergodic process 01 natural sciences Topological entropy in physics Mathematical Sciences Quantum relative entropy 010305 fluids & plasmas Nonlinear Sciences::Chaotic Dynamics quant-ph Condensed Matter::Superconductivity Quantum mechanics Qubit Physical Sciences 0103 physical sciences Quantum system Quantum Physics (quant-ph) 010306 general physics |
| Zdroj: | Neill, C; Roushan, P; Fang, M; Chen, Y; Kolodrubetz, M; Chen, Z; et al.(2016). Ergodic dynamics and thermalization in an isolated quantum system. Nature Physics, 12(11), 1037-1041. doi: 10.1038/nphys3830. Lawrence Berkeley National Laboratory: Lawrence Berkeley National Laboratory. Retrieved from: http://www.escholarship.org/uc/item/1th2w9zv Nature Physics, vol 12, iss 11 |
| DOI: | 10.1038/nphys3830. |
| Popis: | © 2016 Macmillan Publishers Limited. All rights reserved. Statistical mechanics is founded on the assumption that all accessible configurations of a system are equally likely. This requires dynamics that explore all states over time, known as ergodic dynamics. In isolated quantum systems, however, the occurrence of ergodic behaviour has remained an outstanding question. Here, we demonstrate ergodic dynamics in a small quantum system consisting of only three superconducting qubits. The qubits undergo a sequence of rotations and interactions and we measure the evolution of the density matrix. Maps of the entanglement entropy show that the full system can act like a reservoir for individual qubits, increasing their entropy through entanglement. Surprisingly, these maps bear a strong resemblance to the phase space dynamics in the classical limit; classically, chaotic motion coincides with higher entanglement entropy. We further show that in regions of high entropy the full multi-qubit system undergoes ergodic dynamics. Our work illustrates how controllable quantum systems can investigate fundamental questions in non-equilibrium thermodynamics. |
| Databáze: | OpenAIRE |
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