Assistant Professor Shinsei Ryu has been awarded the 27th Nishinomiya-Yukawa Memorial Prize for outstanding research in theoretical physics for his “Holographic Derivation of Entanglement Entropy from the anti-de Sitter Space/Conformal Field Theory Correspondence,” published in the May 9, 2006, issue of Physical Review Letters. Ryu shares the prize with his collaborator and coauthor, Tadashi Takayanagi, a professor of physics at Yukawa Institute for Theoretical Physics at Kyoto University.
In their study on quantum entanglement, Ryu and Takayanagi apply the concept of holographic principle from superstring theory to the measurement of quantum states, called entanglement entropy, used in quantum field theories, to address persistent gaps in superstring theory.
Superstring theory attempts to explain all of the particles and fundamental forces of nature by one universal theory, treating matter, force, and gravity in a fully quantum mechanical way. However, superstring theory has not yet been fully successful in treating spacetime in a fully quantum mechanical way, particularly as applied to black holes and the genesis of spacetime.
Ryu and Takayanagi address these gaps using the concept of holographic principle to describe quantum entanglement. The holographic principle suggests that quantum field theories in non-gravitating spacetime are a “shadow” of gravitational theory in one higher dimension.
Using the holographic principle, quantum entanglement in quantum field theories is described in terms of a geometrical quantity, given by the area in the dual gravity theory. This suggests an interpretation of the entropy of a black hole in terms of quantum entanglement, revealing an important aspect of quantum gravity. It also gives great insight into strongly interacting quantum field theories.
Ryu received his bachelor’s degree (2000) in physics and his master’s (2002) and doctoral (2005) degrees in applied physics from the University of Tokyo. In 2001, he received the Tanaka Shoji Prize (master’s thesis prize) from the Department of Applied Physics at the University of Tokyo. He was awarded a research fellowship by the Japan Society for the Promotion of Science (2002–3). He was awarded Japan’s 7th Condensed Matter Science Prize (2012) for his development of a “periodic table” for the classification of topological phases of matter in three spatial dimensions.
The Nishinomiya-Yukawa Memorial Prize is presented to promising young physicists under 40 years of age by the City of Nishinomiya to encourage research in theoretical physics. The award was established by the city to honor Dr. Hideki Yukawa, the first Japanese Nobel laureate in physics, who developed the meson theory while living in Kurakuen in Nishinomiya.
Ryu and Takayanagi will be presented with the award in a ceremony in Nishinomiya, Japan, on November 1, 2013.
This research was funded in part by the National Science Foundation under grant number PHY99-07949. The conclusions presented are those of the scientists and not necessarily those of the funding agency.