eprintid: 1394114 rev_number: 38 eprint_status: archive userid: 608 dir: disk0/01/39/41/14 datestamp: 2013-05-23 05:13:40 lastmod: 2021-10-04 01:19:36 status_changed: 2013-10-02 09:35:01 type: article metadata_visibility: show item_issues_count: 0 creators_name: Webster, CH creators_name: Fenton, JC creators_name: Hongisto, TT creators_name: Giblin, SP creators_name: Zorin, AB creators_name: Warburton, PA title: NbSi nanowire quantum phase-slip circuits: dc supercurrent blockade, microwave measurements, and thermal analysis ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F64 note: © 2013 American Physical Society abstract: We present a detailed report of microwave irradiation of ultranarrow superconducting nanowires. In our nanofabricated circuits containing a superconducting NbSi nanowire, a dc blockade of current flow was observed at low temperatures below a critical voltage Vc, a strong indicator of the existence of quantum phase-slip (QPS) in the nanowire. We describe the results of applying microwaves to these samples, using a range of frequencies and both continuous-wave and pulsed drive, in order to search for dual Shapiro steps which would constitute an unambiguous demonstration of quantum phase-slip. We observed no steps, and our subsequent thermal analysis suggests that the electron temperature in the series CrO resistors was significantly elevated above the substrate temperature, resulting in sufficient Johnson noise to wash out the steps. To understand the system and inform future work, we have constructed a numerical model of the dynamics of the circuit for dc and ac bias (both continuous-wave and pulsed drive signals) in the presence of Johnson noise. Using this model, we outline important design considerations for device and measurement parameters which should be used in any future experiment to enable the observation of dual Shapiro steps at experimentally accessible temperatures and, thus, lead to the development of a QPS-based quantum current standard. date: 2013-04-01 official_url: http://dx.doi.org/10.1103/PhysRevB.87.144510 vfaculties: VMPS oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_source: WoS-Lite elements_id: 871313 doi: 10.1103/PhysRevB.87.144510 lyricists_name: Fenton, Jonathan lyricists_name: Warburton, Paul lyricists_id: JCFEN40 lyricists_id: PAWAR27 full_text_status: public publication: Physical Review B volume: 87 number: 14 article_number: 144510 issn: 1098-0121 citation: Webster, CH; Fenton, JC; Hongisto, TT; Giblin, SP; Zorin, AB; Warburton, PA; (2013) NbSi nanowire quantum phase-slip circuits: dc supercurrent blockade, microwave measurements, and thermal analysis. Physical Review B , 87 (14) , Article 144510. 10.1103/PhysRevB.87.144510 <https://doi.org/10.1103/PhysRevB.87.144510>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1394114/2/e144510.pdf