BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Germain Tobar (Stockholm University) DTSTART:20260127T080000Z DTEND:20260127T093000Z DTSTAMP:20260417T072159Z UID:3cqfs/36 DESCRIPTION:Title: Q uantum metasurfaces as probes of vacuum particle content\nby Germain T obar (Stockholm University) as part of Tricontinental Quantum Fundamentals Seminar\n\n\nAbstract\nThe quantum vacuum of the electromagnetic field is inherently entangled across distinct spatial sub-regions\, resulting in e ntangled particle content across these sub-regions. However\, accessing th is particle content in a controlled laboratory experiment has remained out of experimental reach. Here we propose to overcome this challenge with a quantum mirror made from a two-dimensional sub-wavelength array of atoms t hat divides a photonic cavity. The array's response to light is tunable be tween transmissive and reflective states by a control atom that is excited to a Rydberg state. We find that vacuum photon content from non-perturbat ive changes of the boundary conditions and therefore distinct spatial sub- regions of the vacuum causes subtle frequency shifts that are accessible t o sub-wavelength atom array platforms. This novel approach for probing vac uum particle content stems from the system’s unique ability to create co herent dynamics of superpositions of transmissive and reflective states\, providing a quantum-enhanced platform for observing vacuum particle creati on from highly non-perturbative boundary condition changes of the electrom agnetic field vacuum.\n LOCATION:https://researchseminars.org/talk/3cqfs/36/ END:VEVENT END:VCALENDAR