Signature of preformed pairs in angle-resolved photoemission spectroscopy

Kovač, Klemen (author), Nocera, Alberto (author), Damascelli, Andrea (author), Bonča, Janez (author), Berciu, Mona (author)

We use density matrix renormalization group (DMRG) and variational exact diagonalization (VED) to calculate the single-electron removal spectral weight for the Hubbard-Holstein model at low electron densities. Tuning the strength of the electron-phonon coupling and of the Hubbard repulsion allows us to contrast the results for a liquid of polarons versus a liquid of bipolarons. The former shows spectral weight up to the Fermi energy, as expected for a metal. The latter has a gap in its spectral weight, set by the bipolaron binding energy, although this is also a (strongly correlated) metal. This difference suggests that angle-resolved photoemission spectroscopy could be used to identify liquids of pre-formed pairs. Furthermore, we show that the one-dimensional liquid of incoherent bipolarons is well approximated by a“Bose sea” of bosons that are hard-core in momentum space, occupying the momenta inside the Fermi sea but otherwise noninteracting. This new proposal for a strongly correlated many-body wave function opens the way for studying various other properties of incoherent (nonsuperconducting) liquids of preformed pairs in any dimension.

• Language: English
• Keywords: condensed matter physics, strongly correlated electrons
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2025
• Number of pages: Str. 096502-1-096502-8
• Numbering: Vol. 134, iss. 9
• PID: 20.500.12556/RUL-167665
• UDC: 538.9
• ISSN on article: 0031-9007
• DOI: 10.1103/PhysRevLett.134.096502
• COBISS.SI-ID: 228038147
• Publication date in RUL: 05.03.2025

Record is a part of a journal

• Title: Physical review letters
• Shortened title: Phys. rev. lett.
• Publisher: American Physical Society
• ISSN: 0031-9007
• COBISS.SI-ID: 1282575

Secondary language

• Language: Slovenian
• Keywords: fizika kondenzirane snovi, močno korelirani elektroni

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P1-0044-2022
• Name: Teorija trdnih snovi in statistična fizika