BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//SFP Alpes - ECPv6.16.4.1//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:SFP Alpes
X-ORIGINAL-URL:https://sfp-alpes.fr
X-WR-CALDESC:Évènements pour SFP Alpes
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Paris
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20250330T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20251026T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20260329T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20261025T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20270328T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20271031T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260625T140000
DTEND;TZID=Europe/Paris:20260625T150000
DTSTAMP:20260529T143015Z
CREATED:20260529T142941Z
LAST-MODIFIED:20260529T143015Z
UID:10000172-1782396000-1782399600@sfp-alpes.fr
SUMMARY:Benjamin BACQ-LABREUIL (IPCMS\, Université Strasbourg)
DESCRIPTION:The Role of the Apical Oxygen in Cuprate High-Temperature Superconductors\nRésumé : \nScanning tunneling microscopy measurements exploiting the natural superstructure modulation of the cuprate superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi-2212) have revealed a possible correlation between the Cu-apical-O distance and the superconducting order parameter\, as reported recently by O’Mahony et al. [1]. These observations were interpreted as evidence for a direct link between superconductivity and the charge-transfer gap\, and more broadly revived the long-standing question of the role of apical oxygens in cuprate superconductivity. In this talk\, I will discuss the impact of apical oxygen displacement on the superconducting properties of Bi$_2$Sr$_2$CuO$_{6+x}$\, Bi-2212\, and HgBa$_2$CuO$_{4+x}$ [2]\, leveraging a recently developed first-principles framework for high-temperature superconductors [3]. The quantitative agreement between our calculations and experiments allows us to unambiguously attribute the observed variations of superconducting order parameter to changes in the apical distance. We demonstrate\, however\, that the latter controls the former predominantly via the effective hole-doping of the CuO$_2$ planes\, with negligible effect on the charge-transfer gap. The modest magnitude of the order parameter modulation induced by apical-oxygen displacement alone therefore warrants caution in interpreting correlations between $T_c$ and the apical distance inferred from comparisons across different cuprate compounds. \n[1] O’Mahony\, et al.\, Proc. Natl. Acad. Sci. 119\, e2207449119 (2022) \n[2] S. Vadnais\, et al.\, arXiv:2601.16017 (2026) \n[3] B. Bacq-Labreuil\, et al.\, Phys. Rev. X 15\, 021071 (2025) \n_ \nContact : florence.levy-bertrand@neel.cnrs.fr 
URL:https://sfp-alpes.fr/event/benjamin-bacq_labreuil-ipcms-universite-strasbourg/
LOCATION:CNRS – Salle Rémy Lemaire (K223)\, CNRS - Institut Néel 25 avenue des Martyrs\, Grenoble\, 38042\, France
CATEGORIES:Séminaire
END:VEVENT
END:VCALENDAR