BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Tommy Moorcroft (University of East Anglia) DTSTART:20250304T130000Z DTEND:20250304T140000Z DTSTAMP:20260423T023934Z UID:UEA_mth/20 DESCRIPTION:Title: The meta-stable and stable thermal equilibrium of a photonic mesh lattice \nby Tommy Moorcroft (University of East Anglia) as part of Fluids and Structures Seminar @ UEA\n\n\nAbstract\nn the limit of short optical puls es\, an optical double loop experiment can be modelled using a photonic me sh lattice describing a system of coupled wave fields in discrete space an d time. For an alternating phase modulation\, the photonic mesh lattice po ssesses a linear dispersion relation with two bands that are completely is olated. Here we study the process of thermalisation of a single band\, us ing the framework of weak wave turbulence. Previous experimental and numer ical observations suggest that for single band excitation\, a Rayleigh-Jea ns distribution is observed among the normal modes\, seeming to reach a th ermal equilibrium [1]. However\, for longer time scales\, a power leakage process occurs destabilising the single band Rayleigh-Jeans. Eventually th e power is equally split between bands\, reaching a full thermal equilibri um in both bands simultaneously\, with the total linear energy tending to zero. As a consequence of this\, the temperature and chemical potential ar e now dependent on one another and cannot be arbitrarily chosen.\n\n[1] A. L. Marques Muniz and F. O. Wu and P. S. Jung and M. Khajavikhan and D. N. Christodoulides and U. Peschel : Observation of photon-photon thermodynam ic processes under negative optical temperature conditions Science 379 n.6 636\, 1019-1023 (2023)\n LOCATION:https://researchseminars.org/talk/UEA_mth/20/ END:VEVENT END:VCALENDAR