Professor Peter Andreas GrÃ 1\/4 nberg is a German physicist who was born on May 18 , 1939 . Professor GrÃ 1\/4 nberg won the 2007 Nobel Prize in Physics for his discovery of giant magnetoresistance which made gigabyte hard disk drives easier to produce . Peter Andreas GrÃ 1\/4 nberg ( born 18 May 1939 ) is a German physicist , and Nobel Prize in Physics laureate for his discovery with Albert Fert of giant magnetoresistance which brought about a breakthrough in gigabyte hard disk drives .