▁the ▁Admir alty ▁Sign als ▁Est ab lish ment ▁( now ▁part ▁of ▁the ▁Admir alty ▁Research ▁Est ab lish ment ) ▁to ▁work ▁on ▁rad ar . ▁In ▁ 1 9 4 4 ▁he ▁joined ▁the ▁British ▁atomic ▁energy ▁team ▁in ▁Montreal ▁design ing ▁nuclear ▁react ors , ▁but ▁in ▁ 1 9 4 5 ▁returned ▁to ▁England , ▁first ▁to ▁Cambridge ▁and ▁then ▁in ▁ 1 9 4 6 ▁to ▁Oxford , ▁where ▁he ▁was ▁appointed ▁Wy ke ham ▁Professor ▁of ▁Physics . ▁ ▁Among ▁of ▁his ▁doctor al ▁students ▁were ▁An ato le ▁Ab rag am ▁and ▁John ▁C live ▁Ward . ▁In ▁ 1 9 4 7 , ▁in ▁collaboration ▁ ▁with ▁John ▁Ward , ▁he ▁co - author ed ▁a ▁paper ▁that ▁origin ated ▁on ▁the ▁probability ▁amplitude ▁of ▁two ▁ent ang led ▁quant a ▁propag ating ▁in ▁opposite ▁directions . ▁ ▁In ▁ 1 9 5 0 , ▁when ▁Klaus ▁F uchs , ▁head ▁of ▁the ▁theoretical ▁physics ▁group ▁at ▁A ERE , ▁Har well , ▁was ▁arrested ▁for ▁supp lying ▁atomic ▁secre ts ▁to ▁the ▁USS R , ▁Maurice ▁also ▁served ▁part - time ▁as ▁his ▁replacement . ▁In ▁ 1 9 5 4 ▁he ▁moved ▁to ▁the ▁University ▁of ▁Br istol ▁as ▁Head ▁of ▁the ▁Physics ▁Department . ▁In ▁ 1 9 6 4 ▁he ▁went ▁back ▁to ▁North ▁America , ▁first ▁to ▁the ▁University ▁of ▁Southern ▁California ▁and ▁then ▁in ▁ 1 9 6 8 ▁to ▁the ▁University ▁of ▁British ▁Columbia . ▁From ▁