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Collisions of false-vacuum bubble walls in a quantum spin chain

Milsted, Ashley and Liu, Junyu and Preskill, John and Vidal, Guifre (2020) Collisions of false-vacuum bubble walls in a quantum spin chain. . (Unpublished)

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We study the real-time dynamics of a small bubble of "false vacuum" in a quantum spin chain near criticality, where the low-energy physics is described by a relativistic (1+1)-dimensional quantum field theory. Such a bubble can be thought of as a confined kink-antikink pair (a meson). We carefully construct bubbles so that particle production does not occur until the walls collide. To achieve this in the presence of strong correlations, we extend a Matrix Product State (MPS) ansatz for quasiparticle wavepackets [Van Damme et al., arXiv:1907.02474 (2019)] to the case of confined, topological quasiparticles. By choosing the wavepacket width and the bubble size appropriately, we avoid strong lattice effects and observe relativistic kink-antikink collisions. We use the MPS quasiparticle ansatz to detect scattering outcomes: In the Ising model, with transverse and longitudinal fields, we do not observe particle production despite nonintegrability (supporting recent observations of nonthermalizing mesonic states). With additional interactions, we see production of confined and unconfined particle pairs. Although we simulated these low-energy, few-particle events with moderate resources, we observe significant growth of entanglement with energy and with the number of collisions, suggesting that increasing either will ultimately exhaust our methods. Quantum devices, in contrast, are not limited by entanglement production, and promise to allow us to go far beyond classical methods. We anticipate that kink-antikink scattering in 1+1 dimensions will be an instructive benchmark problem for relatively near-term quantum devices.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Liu, Junyu0000-0003-1669-8039
Preskill, John0000-0002-2421-4762
Additional Information:AM completed this work prior to joining Amazon. We thank Alex Buser, Marcela Carena, Cliff Cheung, Natalie Klco, Ying-Ying Li, Spiros Michalakis, Nicola Pancotti, Burak Sahinoglu, Martin Savage and Eugene Tang for useful discussions and comments. This material is based upon work supported in part by the U.S. Department of Energy Office of Science, Office of Advanced Scientific Computing Research, (DE-NA0003525, DE-SC0020290), and Office of High Energy Physics (DE-ACO2-07CH11359, DE-SC0018407). AM, JL and JP also acknowledge funding provided by the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center (NSF Grant PHY-1733907), the Simons Foundation It from Qubit Collaboration, and the Air Force Office of Scientific Research (FA9550-19-1-0360). GV is a CIFAR fellow in the Quantum Information Science Program. Sandbox is a team within the Alphabet family of companies, which includes Google, Verily, Waymo, X, and others. Research at Perimeter Institute is supported in part by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Colleges and Universities. Some of the computations presented here were conducted on the Caltech High Performance Cluster, partially supported by a grant from the Gordon and Betty Moore Foundation.
Group:Walter Burke Institute for Theoretical Physics, Institute for Quantum Information and Matter, AWS Center for Quantum Computing
Funding AgencyGrant Number
Department of Energy (DOE)DE-NA0003525
Department of Energy (DOE)DE-SC0020290
Department of Energy (DOE)DE-ACO2-07CH11359
Department of Energy (DOE)DE-SC0018407
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
Simons FoundationUNSPECIFIED
Air Force Office of Scientific Research (AFOSR)FA9550-19-1-0360
Canadian Institute for Advanced Research (CIFAR)UNSPECIFIED
Department of Innovation, Science and Economic Development (Canada)UNSPECIFIED
Ontario Ministry of Colleges and UniversitiesUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
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Record Number:CaltechAUTHORS:20210512-104051553
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109100
Deposited By: George Porter
Deposited On:12 May 2021 19:20
Last Modified:12 May 2021 19:20

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