--- _id: '1114' abstract: - lang: eng text: Nonequilibrium phase transitions exist in damped-driven open quantum systems when the continuous tuning of an external parameter leads to a transition between two robust steady states. In second-order transitions this change is abrupt at a critical point, whereas in first-order transitions the two phases can coexist in a critical hysteresis domain. Here, we report the observation of a first-order dissipative quantum phase transition in a driven circuit quantum electrodynamics system. It takes place when the photon blockade of the driven cavity-atom system is broken by increasing the drive power. The observed experimental signature is a bimodal phase space distribution with varying weights controlled by the drive strength. Our measurements show an improved stabilization of the classical attractors up to the millisecond range when the size of the quantum system is increased from one to three artificial atoms. The formation of such robust pointer states could be used for new quantum measurement schemes or to investigate multiphoton phases of finite-size, nonlinear, open quantum systems. article_number: '011012' article_processing_charge: Yes author: - first_name: Johannes M full_name: Fink, Johannes M id: 4B591CBA-F248-11E8-B48F-1D18A9856A87 last_name: Fink orcid: 0000-0001-8112-028X - first_name: András full_name: Dombi, András last_name: Dombi - first_name: András full_name: Vukics, András last_name: Vukics - first_name: Andreas full_name: Wallraff, Andreas last_name: Wallraff - first_name: Peter full_name: Domokos, Peter last_name: Domokos citation: ama: Fink JM, Dombi A, Vukics A, Wallraff A, Domokos P. Observation of the photon blockade breakdown phase transition. Physical Review X. 2017;7(1). doi:10.1103/PhysRevX.7.011012 apa: Fink, J. M., Dombi, A., Vukics, A., Wallraff, A., & Domokos, P. (2017). Observation of the photon blockade breakdown phase transition. Physical Review X. American Physical Society. https://doi.org/10.1103/PhysRevX.7.011012 chicago: Fink, Johannes M, András Dombi, András Vukics, Andreas Wallraff, and Peter Domokos. “Observation of the Photon Blockade Breakdown Phase Transition.” Physical Review X. American Physical Society, 2017. https://doi.org/10.1103/PhysRevX.7.011012. ieee: J. M. Fink, A. Dombi, A. Vukics, A. Wallraff, and P. Domokos, “Observation of the photon blockade breakdown phase transition,” Physical Review X, vol. 7, no. 1. American Physical Society, 2017. ista: Fink JM, Dombi A, Vukics A, Wallraff A, Domokos P. 2017. Observation of the photon blockade breakdown phase transition. Physical Review X. 7(1), 011012. mla: Fink, Johannes M., et al. “Observation of the Photon Blockade Breakdown Phase Transition.” Physical Review X, vol. 7, no. 1, 011012, American Physical Society, 2017, doi:10.1103/PhysRevX.7.011012. short: J.M. Fink, A. Dombi, A. Vukics, A. Wallraff, P. Domokos, Physical Review X 7 (2017). date_created: 2018-12-11T11:50:13Z date_published: 2017-01-31T00:00:00Z date_updated: 2023-09-20T11:33:07Z day: '31' ddc: - '539' department: - _id: JoFi doi: 10.1103/PhysRevX.7.011012 external_id: isi: - '000397450500001' file: - access_level: open_access content_type: application/pdf creator: system date_created: 2018-12-12T10:12:52Z date_updated: 2018-12-12T10:12:52Z file_id: '4972' file_name: IST-2017-753-v1+1_PhysRevX.7.011012.pdf file_size: 1172926 relation: main_file file_date_updated: 2018-12-12T10:12:52Z has_accepted_license: '1' intvolume: ' 7' isi: 1 issue: '1' language: - iso: eng month: '01' oa: 1 oa_version: Published Version publication: Physical Review X publication_identifier: issn: - '21603308' publication_status: published publisher: American Physical Society publist_id: '6252' pubrep_id: '753' quality_controlled: '1' scopus_import: '1' status: public title: Observation of the photon blockade breakdown phase transition tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 7 year: '2017' ...