1 arXiv version 1 (quant-ph)                             ! " #$"%  ! & ’ (  ) *+,- .   /0 ’ ! 1.) ’ ). 2 3(  ) 4 ’ ( 5 ) *&*+ 0 !  .  )!  !0  )   !.  .! ! ) . ’ )6  . 7  8. . ! #)  (%  !   .  !0 ) ( 7    .)  . ) 9 ! .  .)   ) ! ( ) . !    ... #:%   ) #"%  )   !. !  ) ; <  !    )   0 ! .  ) . !  ) ) !  3#% . =1> ,5+&? *5+5@0 *545@ Contact: Dr S. G. Tan Division of Spintronic, Media and Interface Data Storage Institute (Agency for Science and Technology Research) DSI Building 5 Engineering Drive 1 (Off Kent Ridge Crescent, NUS) Singapore 117608 DID: 65-6874 8410 Mobile: 65-9446 8752