Career: Research chemist at the National Institutes of Health, 1955-1956; Post doctoral fellow at the National Bureau of Standards, 1960-1961. He was called to active military service at the U.S. Air Force Academy in 1961 as an Assistant Professor of Physics at The U.S. Air Force Academy, 1961-1964; Concurrent post as theoretical physicist at the Denver Research Institute, 1962-1964; Research Physicist at the Lawrence Radiation Laboratory, 1964-1972; Associate Director of the Lawrence Hall of Science, 1972-1975; Assistant Dean of the College of Letters & Science at UC-Berkeley; Associate Professor of Physics at UC-Berkeley, 1972-1975, and Professor of Physics, 1975 until retirement. Was visiting professor at the University of Colorado, MIT, and Howard University. He is a Fellow of the American Physical Society.

Research Interests

My research interests are in quantum liquid theory and in the foundations of quantum statistical physics. I have studied the phenomenon of superfluidity in interacting Bose systems. This work has been concerned with the spectrum of elementary excitations which provide the basis for the thermodynamic properties of quantum liquids.

We have found theorems which govern the macroscopic quantization of superfluid flow. Currently, I have been investigating the topological structure of two dimensional quantum liquids and the question of symmetries and broken symmetries.

We have developed a microscopic theory of the genesis of the vortex component of the excitation spectrum of two dimensional Bose systems.

**Projects**

I have been interested in the occurrence of macroscopic quantization in many body systems. Byers and Yang have shown that the quantization of magneticflux in amultiply connected superconductor can be understood as a consequence of the Meissner effect together with the singled-valued character of the many-body wave functions, and general principles of statistical mechanics. With John Garrison and Jack Wong, I have found that the quantization of circulation in super-fluid helium can be understood in an analogous manner. We have shown that the free energy of a vortex system has the Byers Yang property of being periodic and even in the circulation with period h/m. This leads to the prediction of a helium analog of the ac Josephson effect.

I have explored the issue of long range order in thin films with Garrison and Wong. For many body systems with smooth potentials we have found generalizations of the Hohenberg Mermin Wagner theorem. We have shown that an equilibrium state for a homogeneous thin film is necessarily invariant under any continuous internal symmetry group generated by a conserved density. The absence of long range order follows from its relation to broken symmetry. This work has taken us into the area of algebraic methods of quantum field theory and the Kubo-Martin-Schwinger boundary condition.

I have had a continuing interest in the elementary excitation spectrum of interacting Bose systems. I have studied the algebra of currents and densities toward this end. These are natural collective coordinates. At lowest order one recovers the Bogoliubov-Zubarev theory of collective excitations. However, one can easily go further. With Uwe Albertin (a former graduate student), I have found that the elementary excitation spectrum for a Bose liquid decomposes into an algebraic part and a topological part. These correspond to quasiparticles and pseudoparticles (vortices). Within the formalism of current algebra the fundamental tool is the Helmholtz decomposition of the current operator. One obtains the Bogoliubov spectrum associated to the density and the longitudinal part of the current density. The contribution of the transversepart of the current density yields the Hamitonian for vortex-vortex interactions.The current algebra provides a microscopic basis for the methods of Rasetti and Regge in their theory of quantum vorticity.

With Achilles D. Speliotopoulos (a former graduate student), I have studied the dynamics of the vortex system that one obtains for two dimensional Bose systems. A Lagrangian is derived from the current algebra representation of the microscopic theory. In the constant density approximation, one obtains Kirchoff 's equations for the motion of the vortices in the plane. The energy of the vortex system is the Kosterlitz-Thoulesscoulombic interaction. We have studied the symmetries of the vortex Lagrangian to identify those constants of the motion which determine the appropriate ensemble for the statistical mechanics of the vortex gas. This leads to the underlying principles for the partition function of Kosterlitz and makes contact with the Kosterlitz-Thouless phase transition mechanism.

**Selected Publications**

Dr. Morrison specialized in an area of theoretical physics called statistical mechanics. For many years the only UC Berkeley faculty member in that field, he attempted to understand the behavior of fluids when the temperature drops low enough for them to become so-called superfluids. In this state they exhibit peculiar quantum properties, ranging from flow without resistance to the generation of quantized vortices by spinning the container.

12. Speliotopoulos, Achilles D.; **Morrison, Harry L.** __Observations on the dynamics of the two-dimensional vortex gas on compact Riemann surfaces__. J. Phys. A **26** (1993), no. 14, 3527--3543.

11. Speliotopoulos, Achilles D.; **Morrison, Harry L.** __The nature of symmetry breaking in the superfluid phase transition in two dimensions__. Modern Phys. Lett. B **8** (1994), no. 6, 381--392.

10. Speliotopoulos, Achilles D.; **Morrison, Harry L.** __On the Kosterlitz-Thouless transition on compact Riemann surfaces__. Modern Phys. Lett. B **7** (1993), no. 3, 171--182.

9. Albertin, Uwe K.; **Morrison, Harry L.** __Representations of the diffeomorphism group describing an infinite Bose gas in the presence of ideal vortex filaments__. J. Math. Phys. **31** (1990), no. 6, 1535--1543.

8. Welsh, A. H.; **Morrison, H. L.** __Robust $L$ estimation of scale with an application in astronomy__. J. Amer. Statist. Assoc. **85** (1990), no. 411, 729--743. 62F35

7. Speliotopoulos, Achilles D.; **Morrison, Harry L.** __The Hodge decomposition and the vortex Hamiltonian__. Phys. Lett. A **141** (1989), no. 5-6, 278--284.

6. Albertin, Uwe K.; **Morrison, Harry L.** __Current algebras and liquid helium__. Phys. A **159** (1989), no. 2, 188--220.

5. Lindesay, James V.; **Morrison, Harry L. **__The geometry of quantum flow__. Mathematical analysis of physical systems, 135--167, Van Nostrand Reinhold, New York-London, 1985.

4. Creswick, Richard J.; **Morrison, Harry L.** __On the dynamics of quantum vortices__. Phys. Lett. A **76** (1980), no. 3-4, 267--268.

3. Garrison, John C.; Wong, Jack; **Morrison, Harry L. **__Absence of long-range order in thin films__. J. Mathematical Phys. **13 **(1972), 1735--1742.

2. Garrison, John C.; **Morrison, Harry L.**; Wong, Jack __Galilean relativity, locality, and quantum hydrodynamics__. J. Mathematical Phys. **11**1970 630--634.

1. **Morrison, H. L.** __The quantum theory of many-particle systems__. International Science Review Series, Vol. II Gordon and Breach Science Publishers, New York-London 1962 xiv+345 pp. ???