Detecting Anomalous Dimensions in the Strange Metal Phase of the Cuprates

14/06/2017 @ 11:00 AM – 12:30 PM Asia/Singapore Timezone
Physics Conference Room (S11-02-07)

Speaker: Prof Philip W. Phillips
Abstract Details: We all learned that conserved quantities such as the current in a metal cannot acquire an anomalous dimension in any theory that respects charge conservation. A recent theory of the strange metal of the cuprates has reached the conclusion that all of the properties of this phase can be understood if the current does in fact acquire an anomalous dimension.  I will show how this seemingly contradictory prediction can be understood and also show that a finger print of such an anomaly is the Aharanov-Bohm flux through a strange metal ring. In the presence of an anomalous dimension, the AB phase deviates strikingly from the standard result and offers a precise diagnostic as to what is strange about the strange metal. I will also construct a Virasoro algebra for such anomalous currents and show that they correspond to a new class of non-local yet conformal theories.

About the Speaker: Philip Phillips is a theoretical condensed matter physicist who has an international reputation for his work on transport in disordered and strongly correlated low-dimensional systems. He is the inventor of various models for Bose metals, Mottness, and the random dimer model, which exhibits extended states in one dimension, thereby representing an exception to the localization theorem of Anderson's.

His research focuses sharply on explaining current experimental observations that challenge the standard paradigms of electron transport and magnetism in solid state physics. Departures from paradigms tell us that there is much to learn. Such departures are expected to occur in the presence of strong-electron interactions, disorder, and in the vicinity of zero-temperature quantum critical points. The common question posed by experiments that probe such physics is quite general. Simply, how do strong Coulomb interactions and disorder conspire to mediate zero-temperature states of matter? It is precisely the strongly interacting electron problem or any strongly coupled problem for that matter, such as quark confinement, that represents one of the yet-unconquered frontiers in physics. Understanding the physics of strong coupling is Phillips' primary focus. In latter years, he has developed a number of approaches to the physics of cuprate high-Tc superconductors based on the gauge/gravity duality or the AdS/CFT conjecture, in which a strongly coupled quantum theory is mapped onto a weakly interacting theory of gravity, and he is one of the visible players in this field of mapping string theory and other models/tools from quantum gravity to condensed matter settings.

Professor Phillips received his bachelor's degree from Walla Walla College in 1979, and his Ph.D. from the University of Washington in 1982. After a Miller Fellowship at Berkeley, he joined the faculty at Massachusetts Institute of Technology (1984-1993). He joined the University of Illinois in 1993.