▁at ▁the ▁Abd us ▁Sal am ▁International ▁Centre ▁for ▁The oret ical ▁Physics ▁( I CT P ), ▁both ▁in ▁Tri este , ▁Italy . ▁ ▁He ▁is ▁a ▁broad - scope ▁the or ist ▁who ▁carried ▁out ▁research ▁on ▁a ▁ ▁wide ▁range ▁of ▁cond ensed ▁matter ▁physics ▁phen omena . ▁His ▁early ▁work ▁de alt ▁with ▁optical ▁properties , ▁electron ▁energy ▁loss , ▁theory ▁of ▁exc it ons ▁and ▁non local ▁die lect ric ▁response ▁ ▁in ▁sol ids , ▁including ▁layer ▁cry st als ▁such ▁as ▁graph ite ▁and ▁sem icon duct ors ; ▁charge - ▁and ▁spin - dens ity - w aves ; ▁ ▁surface ▁physics ▁in ▁all ▁its ▁aspects , ▁particularly ▁reconst ruction , ▁rough ening ▁and ▁mel ting , ▁also ▁in ▁clusters ; ▁the ▁prediction ▁the ▁Ber ry ▁phase ▁in ▁full er ene ; ▁the ▁first ▁calculated ▁ST M ▁map ▁of ▁graph ite , ▁now ▁a ▁standard ▁in ▁the ▁field ; ▁matter ▁at ▁extreme ▁press ures : ▁carbon , ▁o xygen , ▁hydro gen , ▁CO 2 , ▁iron ▁at ▁earth ▁core ▁conditions , ▁water ▁and ▁am mon ia ▁at ▁deep ▁planet ary ▁conditions , ▁pressure - indu ced ▁ins ulator - met al ▁trans itions ▁in ▁layer ▁comp ounds ▁like ▁Mo S 2 . ▁In ▁nan oph ys ics , ▁he ▁and ▁his ▁group ▁predicted ▁hel ical ▁structures ▁of ▁metal ▁nan ow ires ; ▁the ▁sp ont aneous ▁magnet ism ▁of ▁metal ▁n ano contact s , ▁including ▁the ▁electronic ▁circumstances ▁for ▁normal ▁or ▁fer