Anomalous density fluctuations in a strange metal
[1];
- Department of Physics, University of Illinois at Urbana–Champaign, Urbana, IL 61801,, Materials Research Laboratory, University of Illinois at Urbana–Champaign, Urbana, IL 61801,
- Institute for the Theory of Condensed Matter, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany,
- Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73069,
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973
A central mystery in high-temperature superconductivity is the origin of the so-called strange metal (i.e., the anomalous conductor from which superconductivity emerges at low temperature). Measuring the dynamic charge response of the copper oxides, χ"(q,ω), would directly reveal the collective properties of the strange metal, but it has never been possible to measure this quantity with millielectronvolt resolution. Here, we present a measurement of χ"(q,ω) for a cuprate, optimally doped Bi2.1Sr1.9CaCu2O8+x (Tc = 91 K), using momentum-resolved inelastic electron scattering. In the medium energy range 0.1–2 eV relevant to the strange metal, the spectra are dominated by a featureless, temperature- and momentum-independent continuum persisting to the electronvolt energy scale. This continuum displays a simple power-law form, exhibiting q2 behavior at low energy and q2/ω2 behavior at high energy. Measurements of an overdoped crystal (Tc = 50 K) showed the emergence of a gap-like feature at low temperature, indicating deviation from power law form outside the strange-metal regime. In conclusion, our study suggests the strange metal exhibits a new type of charge dynamics in which excitations are local to such a degree that space and time axes are decoupled.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Emergent Superconductivity (CES); Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-98CH10886; SC0012704; GBMF4542; DMR-1352604
- OSTI ID:
- 1438288
- Alternate ID(s):
- OSTI ID: 1462403
- Report Number(s):
- BNL-207872-2018-JAAM
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 115 Journal Issue: 21; ISSN 0027-8424
- Publisher:
- Proceedings of the National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Particle–hole asymmetric superconducting coherence peaks in overdoped cuprates
Consistency between reflection momentum-resolved electron energy loss spectroscopy and optical spectroscopy measurements of the long-wavelength density response of