BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Terahertz spectroscopy of two-dimensional plasmons in grating-gat ed AlGaN/GaN heterostructures DTSTART;VALUE=DATE-TIME:20220706T130000Z DTEND;VALUE=DATE-TIME:20220706T132000Z DTSTAMP;VALUE=DATE-TIME:20260813T160344Z UID:indico-contribution-809@events.ncbj.gov.pl DESCRIPTION:Speakers: Irmantas Kašalynas (THz photonics laboratory\, Cent er for Physical Sciences and Technology\, Vilnius\, Lithuania)\nHigh elect ron mobility and temperature stability of III-nitride heterostructures ser ve as a base for the development of tunable frequency THz emitters. Some T Hz emission results of the 2D plasmons in nitride high electron mobility t ransistor (HEMT) structures have been previously reported\, but they are s till far from commercially viable devices. It is worth noting that the gra phene-based plasmonic metamaterial for THz laser transistors was proposed recently. Nevertheless\, the III-nitride heterostructures as promising pla smonic material were confirmed too by demonstrating possibility of the 2D plasmon excitation up to room temperatures. \nIn this work\, we report on the emission and transmission spectra of the 2D plasmons excited in THz ra nge in grating-gated AlGaN/GaN HEMT structures at the 80 K temperature. Th e plasmonic samples were fabricated by positioning the periodic metal stri pes on top surface of heterostructures over an area of about 2 × 2 mm2. T hree gate-gratings were prepared in the same process on the 10x10 mm2 samp le to minimize fabrication uncertainties and ensure the uniformity of mate rial parameters over the different gratings. The periods of the gratings w ith filling factor of 50 % were selected to be 600 nm\, 800 nm\, and 1000 nm enabling the excitation of fundamental plasmon modes in the frequency r ange of 1 3 THz in wide temperature range. In this work the symmetric 800 nm period gratings were investigated in order to find optimal conditions f or excitation of 2D plasmons under electrical excitation. The ohmic source \, S\, and drain\, D\, contacts to the conductive 2DEG channel were develo ped outside of the grating\, the wave vector of which was oriented perpend icularly to the contacts as described elsewhere. The resonance position an d intensity were found to be related to the grating period and the bias vo ltage applied to the transistor terminals. Moreover\, the Rabi splitting o f 2D plasmon resonance was observed in the emission spectra demonstrating the splitting values to be up to 400 GHz which was considerably larger th an previously reported for the plasmonic samples developed of similar III- nitride heterostructures.\nThis work received funding from the Research Co uncil of Lithuania (Lietuvos mokslo taryba) through project “Hybrid plas monic components for THz range (T-HP)” under Grant No. 01.2.2-LMT-K-718- 03-0096 and was supported by CENTERA Laboratories in frame of the Internat ional Research Agendas program for the Foundation for Polish Sciences co-f inanced by the European Union under the European Regional Development Fund (No. MAB/2018/9).\n\nhttps://events.ncbj.gov.pl/event/75/contributions/80 9/ LOCATION:Novotel Warszawa Centrum Róża URL:https://events.ncbj.gov.pl/event/75/contributions/809/ END:VEVENT END:VCALENDAR