R. G. Herb Condensed Matter Seminars |
Events on Thursday, November 2nd, 2023
- Theory of Pines' demon in multiband metals
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Edwin Huang, Notre Dame
- Abstract: In 1956, David Pines predicted the existence of an acoustic plasmon, dubbed a "demon", in metals with multiple and sufficiently distinct charge carrier species. Despite extensive searches, demons have not been observed directly until recent momentum-resolved electron energy-loss spectroscopy (M-EELS) experiments on Sr2RuO4. Here, we discuss the theoretical conditions for the existence of demons as a stable collective excitation in multiband metals. We find, without any fitting or tuning of parameters, agreement between experimental M-EELS spectra and multi-orbital random phase approximation (RPA) calculations of the charge susceptibility. A decomposition of the calculation of the susceptibility into intra- and inter-band components provides direct evidence of the out-of-phase character of the demon. Our findings thus demonstrate the utility of numerical calculations for the microscopic interpretation of experimental spectroscopy. Nature 621, 66–70 (2023)
- Host: Ilya Esterlis