Bogoliubov 1947 linear canonical transformation of creation/annihilation operators preserving canonical commutation relations; diagonalizes quadratic Hamiltonians; basis of BdG / BCS / squeezed states.
Bogoliubov 1947 linear canonical transformation of creation/annihilation operators preserving canonical commutation relations; diagonalizes quadratic Hamiltonians; basis of BdG / BCS / squeezed states.