Harvey Kaplan

Harvey Kaplan died in New York City on February 11, 2015 after a brief illness. His contributions to solid state physics and condensed matter systems spanned many areas. In his professional career, his published results include studies on the saturation magnetization of ferrites, the electronic structure of molecules, lattice vibrations, localized impurity states in semiconductors, exact solutions for bound states of the Heisenberg model, solitons, piezo-elasticity, and chaos theory.

Harvey graduated from the High School of Music and Art in New York and then received a Diploma of Violin from the Manhattan School of Music in 1943. After graduation, he served in the US Army on Guam and Okinawa and was awarded a bronze star and purple heart. Upon discharge in 1946, he entered the City College of New York and received his Bachelor of Science degree in 1948 with a major in physics. In 1952, he received his PhD from the University of California in Berkeley, working as a student of Charles Kittel; his thesis was on the saturation magnetization of ferrites. For the next two years he held a postdoctoral position at MIT under John C. Slater. His work with Slater culminated in his frequently-cited 1957 publication on the structure of the ground state of the ammonia molecule, enabling comparisons between theory and experiment on the binding energy and dipole moment of the molecule.

After five years at the University of Buffalo, in 1959 Harvey came to Syracuse University as an Assistant Professor, but was promoted to Associate Professor the following year. At Syracuse, he joined a small group of atomic and solid state experimental physicists including John Trischka and Arnold Honig.

At Syracuse, his first research was a study of lattice vibrations in crystals of the zinc-blende structure. Together with graduate student John J. Sullivan, a good fit with data was found for all the important long-wavelength properties of the lattice vibration spectrum for the four crystals GaAs, InSb, AlSb, and ZnS. Their results pointed out that many crystals (e.g., ZnS) have properties whose description falls between the labels “ionic” and “covalent”.

Following this work, he turned his attention to impurity states in semiconductors. In work completed in 1963, he derived several important results on the conditions for the existence of impurity states associated with minima in the energy band; one of the results was a generalization of a result of Slater and Koster. Following this, with graduate student Peter Millet, new exact results on the Heisenberg model were presented in a 1974 publication; in particular, the nature of localized spin states in one, two and three dimensions was clarified.

In the 1980s and 1990s, Harvey’s interests turned to the subject of chaos. As an example of his contributions to this field, in a 1992 Physical Review Letters article, he derived conditions for intermittency (alternating bursts of regular and chaotic behavior) in the quadratic map family, showing its strong dependence on dimensionality.

Harvey never gave up playing the violin. Whenever possible he found other amateur musicians with whom he could play chamber music. His wife Annetta was an accomplished pianist and a teacher of piano playing. Both were active members of the Syracuse Friends of Chamber Music, the Syracuse Society for New Music, and, a performance group, Civic Morning Musicals. Harvey was a virtuoso whistler. The halls of the Physics Building would resonate with his trills and double stops from works of Bach, Beethoven, and other masters. He also was an avid hiker and cyclist. On weekends he frequently took long trips on his bicycle up and down the drumlins that make up the Syracuse geology.

In 1995, Harvey retired from Syracuse University and a year later he joined his pianist partner, Leslie Singer, in New York City. There, he not only played chamber music, but also had an office as a visitor at CUNY. It was during this period of his life that he used the computer to study wave functions forms and interactions. Music and Physics were the basis of his life and he maintained throughout a professional or semi-professional interest in both.

Joshua N. Goldberg
Allen Miller
Department of Physics
Syracuse University