Pseudogap in a crystalline insulator doped by disordered metals

Sae Hee Ryu, Minjae Huh, Do Yun Park, Chris Jozwiak, Eli Rotenberg, Aaron Bostwick and Keun Su Kim ()
Additional contact information
Sae Hee Ryu: Yonsei University
Minjae Huh: Yonsei University
Do Yun Park: Yonsei University
Chris Jozwiak: E. O. Lawrence Berkeley National Laboratory
Eli Rotenberg: E. O. Lawrence Berkeley National Laboratory
Aaron Bostwick: E. O. Lawrence Berkeley National Laboratory
Keun Su Kim: Yonsei University

Nature, 2021, vol. 596, issue 7870, 68-73

Abstract: Abstract Key to our understanding of how electrons behave in crystalline solids is the band structure that connects the energy of electron waves to their wavenumber. Even in phases of matter with only short-range order (liquid or amorphous solid), the coherent part of electron waves still has a band structure. Theoretical models for the band structure of liquid metals were formulated more than five decades ago1–15, but, so far, band-structure renormalization and the pseudogap induced by resonance scattering have remained unobserved. Here we report the observation of the unusual band structure at the interface of a crystalline insulator (black phosphorus) and disordered dopants (alkali metals). We find that a conventional parabolic band structure of free electrons bends back towards zero wavenumber with a pseudogap of 30–240 millielectronvolts from the Fermi level. This is wavenumber renormalization caused by resonance scattering, leading to the formation of quasi-bound states in the scattering potential of alkali-metal ions. The depth of this potential tuned by different kinds of disordered alkali metal (sodium, potassium, rubidium and caesium) allows the classification of the pseudogap of p-wave and d-wave resonance. Our results may provide a clue to the puzzling spectrum of various crystalline insulators doped by disordered dopants16–20, such as the waterfall dispersion observed in copper oxides.

Date: 2021
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/s41586-021-03683-0 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:596:y:2021:i:7870:d:10.1038_s41586-021-03683-0

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-021-03683-0

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().