Frejman Y. Phase transitions in quantum and magnetic molecular cryocrystals

Objects: solid hydrogens, solid oxygen, and cryocrystals doped with oxygen; model systems of quantum and magnetic rotors. Goals: the quest for new quantum systems on the base of quantum rotors and studies of phase transitions in the system of magnetic rotors. Methods: analytical methods of theoretical physics such as Green function formalism, methods of theory of quantum angular momantum, etc. New results: a new physical phenomenon was found called the quantum orientational melting and its main fetures was studied. Introduction: main results were used to predict new experimental phenomena or to provide explanation for existing unexplained experimental data. Employment: the results are important for further development of quantum solid state and low temperature physics.