Douglas Natelson graduated summa cum laude from Princeton University in 1993 with a BSE in Mechanical and Aerospace Engineering and a certificate in Engineering Physics. On a Hertz fellowship he went on to study experimental low temperature condensed matter physics at Stanford University with Douglas Osheroff. After receiving his PhD in 1998, Prof. Natelson spent two years as a postdoctoral member of technical staff at Bell Laboratories (Lucent Technologies) in Murray Hill, NJ. He joined the faculty of the Physics and Astronomy department at Rice in the fall of 2000, and became a fellow of the Rice Quantum Institute. Prof. Natelson received a courtesy appointment in Electrical and Computer Engineering in fall of 2001. He was promoted to Associate Professor in spring of 2006, and full professor in spring of 2010. He became a courtesy appointee of Rice’s Department of Materials Science and NanoEngineering with its inception in 2013. He served as chair of the Department of Physics and Astronomy from 2016 to 2022, and briefly as interim VP for Research in summer 2022.
Strange metal behavior has been observed in materials ranging from high-temperature superconductors to heavy fermion metals. In conventional metals, current is carried by quasiparticles; although it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is challenging to acquire. We measure shot noise to probe the granularity of the current-carrying excitations in nanowires of the heavy fermion strange metal YbRh2Si2.
When compared to conventional metals, shot noise in these nanowires is strongly suppressed. We argue that this suppression can be attributed neither to electron-phonon nor to electron-electron interactions in a Fermi liquid, suggesting that the current is not carried by well-defined quasiparticles in the strange metal regime we probed.
This work sets the stage for similar studies of other strange metals, to test for universality of this response, and ideally for studies in single devices that may be tuned between Fermi liquid and strange metal regimes. It is also important to consider the noise in strongly interacting Fermi liquids, to see if interactions modify the expectations familiar from conventional mesoscopic physics. Time permitting, I will discuss some recent interesting findings in YbAl3, a mixed valence heavy fermion material.