Quantum-critical conductivity of the Dirac fluid in graphene
ORAL
Abstract
Graphene near charge neutrality is expected to behave like a quantum-critical, relativistic plasma—the “Dirac fluid”—in which massless electrons and holes rapidly collide at a rate proportional to temperature. We measure the frequency-dependent optical conductivity of clean micron-scale graphene encapsulated in hexagonal Boron Nitride at electron temperatures between 77 and 300 K using on-chip terahertz spectroscopy. At charge neutrality, we observe the quantum-critical scattering rate characteristic of the Dirac fluid. At higher doping, we uncover two distinct current-carrying modes with zero and nonzero total momenta, a manifestation of relativistic hydrodynamics. Our work reveals the quantum criticality and unusual dynamic excitations near charge neutrality in graphene.
–
Presenters
-
TAIRU LYU
University of California, Berkeley
Authors
-
TAIRU LYU
University of California, Berkeley
-
Patrick R Gallagher
University of California, Berkeley
-
chanshan yang
University of California, Berkeley
-
Feng Wang
University of California - Berkeley, University of California, Berkeley, Physics, UC Berkeley, Department of Physics, University of California at Berkeley, Berkeley, CA 94709, USA, University of California at Berkeley, Lawrence Berkeley National Laboratory and UC Berkeley, UC Berkeley, Physics, University of California, Berkeley