His research focused on statistical mechanics within theoretical physics, and he was known for his demonstration in 1972 of the absence of long-range order in quantum systems in two dimensions, that was a result from the breaking of a continuous symmetry.
[2] During his time as a student, he was a member of Sigma Xi[5] and participated in sessions of the Summer Institute for Theoretical Physics at the University of Colorado, Boulder.
[7][8] In 1972, Morrison joined the faculty of the physics department at the University of California, Berkeley, as an assistant professor.
[2] He was part of the early founding of the statewide academic preparation program Mathematics, Engineering, Science Achievement (MESA), launched in 1970, which focused on increasing enrollment of minority students.
Along with Robert Henry Bragg Jr., as members of the program's Policy Review Board, he taught a survey course titled "The African American Experience in Science and Technology" covering the physical and biological sciences and engineering, and featuring expert speakers to address the role of African Americans in these fields of study.
[7] Over his career, he was a member of numerous professional organizations, including the American Physical Society, where he was a 1971 fellow.
In collaboration with John Garrison and Jack Wong, Morrison made a significant contribution in 1972 by demonstrating "the absence of long-range order in quantum systems in two dimensions, such as in thin superfluid helium films, due to the breaking of a continuous symmetry."
In 1976, following a meeting at Morgan State University, Morrison was part of a group that contributed to the initial plans for the formal NSBP (then called the Society of Black Physicists).