Gao Wins 2004 Simon Prize

May 17 2004

Photo (left-right): Dr. Art Ramirez, Dr. Jane Faggen, Dr. Xuan Gao, and Prof. Aron Pinczuk


The Robert Simon Memorial Prize is awarded annually by the APAM Department to the graduate student who has completed the most outstanding dissertation. This year, Xuan P. A. Gao was the winner of the 2004 Simon Prize.

Dr. Gao received his Ph.D from Columbia in May 2003 and his dissertation was entitled “Metallic Behavior and Metal Insulator Transition of Two Dimensional Holes in GaAs”. He was advised by Prof. Aron Pinczuk, Dr. Arthur Ramirez, and Prof. Allen Mills. Dr. Gao has made many noteworthy contributions to understanding the anomalous metallic behavior and metal-insulator transition of low density two dimensional holes in Gallium Aresenide quantum wells. Gao’s thesis work lends support to a model in which the two dimensional hole liquid, driven by the competition between kinetic energy and Coulomb potential energy, phase separates into a mixture of a localized Fermi liquid phase and a metallic phase below a critical temperature. Other groups had performed similar measurements in which the sample is placed in a parallel magnetic field, but only Gao recognized the essential properties of his samples in this field configuration. In two key publications he recognized that the value of the energy scale for scattering was field independent, and that the metallic behavior was turned into conventional Fermi liquid type localization when then spins are frozen. These results provide convincing evidence of phase separation in low-carrier-density systems, and reveal interesting properties of the intriguing metallic phase in two-dimensions. In this model, the metal-insulator transition at zero magnetic field is explained being due to the localized Fermi liquid phase percolating through the metallic phase as the disorder strength increases.

Dr. Gao received his B.S. in Physics from South China University of Technology in 1998. In the same year, he entered Columbia as a graduate student in Applied Physics and the following year started his thesis work in the laboratory of Dr. Ramirez, at Bell Labs, Lucent Technologies. Gao continued his work under the supervision of Dr. Mills, both at Bell Labs and then at the University of California, Riverside. While at Columbia, Gao was first author on two articles in Physical Review Letters and was a significant contributor to an influential paper published in Nature.

Dr. Gao was a postdoc at Los Alamos National Laboratory from 2003-2005 and at Harvard University from 2005-2007.

History of the Robert Simon Memorial Prize

The Robert Simon Memorial Prize is awarded annually by the Department of Applied Physics and Applied Mathematics to the graduate student who has completed the most outstanding dissertation. Should no graduate student’s dissertation qualify in any given year, the prize may be awarded to either the most outstanding student who has completed a master of science degree in the Department or to the most outstanding graduating senior in the Department. The Department chair in consultation with the Department faculty selects the awardee.

Robert Simon (December 25, 1919–February 11, 2001) received a B.A. degree cum laude in classics from the City College of New York in 1941, where he was elected to Phi Beta Kappa, and an M.A. in mathematics from Columbia University in 1949. Between 1941 and 1944, Mr. Simon was a lieutenant in the United States Armed Forces serving in England, France, and Italy. He participated in the D-Day operation as a navigator for a plane that dropped paratroopers in the vicinity of Omaha Beach. General Dwight Eisenhower personally shook his hand and wished him well the night before the D-Day assault.

Mr. Simon, who was born and lived in New York City, spent a lifetime making valuable contributions to the field of computer science. Starting in 1953, he worked for 15 years at Sperry's Univac Division in various capacities including marketing, planning, systems engineering, systems programming, and information services. He also spent a year working at the Fairchild Engine Division as director of the Engineering Computer Group. He personally directed the establishment of several company computer centers at sites throughout the United States. Between 1969 and 1973, he was a partner with American Science Associates, a venture capital firm. Mr. Simon was a founder and vice president of Intech Capital Corporation and served on its board from 1972 to 1981 and a founder and member of the board of Leasing Technologies International, Inc. from 1983 until his retirement in 1995.

The prize was established in 2001 by Dr. Jane Faggen with additional support from friends and relatives of Mr. Simon.