Angle-resolved photoemission spectroscopy of a Fermi-Hubbard system
| Autor: | Benjamin M. Spar, Waseem Bakr, Thomas P. Devereaux, Edwin W. Huang, Elmer Guardado-Sanchez, Peter Brown |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Condensed Matter::Quantum Gases Optical lattice Hubbard model Condensed matter physics Photoemission spectroscopy Atomic Physics (physics.atom-ph) Quantum Monte Carlo General Physics and Astronomy FOS: Physical sciences Angle-resolved photoemission spectroscopy 01 natural sciences Physics - Atomic Physics 010305 fluids & plasmas Superfluidity Quantum Gases (cond-mat.quant-gas) Condensed Matter::Superconductivity 0103 physical sciences Quantum system Condensed Matter::Strongly Correlated Electrons Condensed Matter - Quantum Gases 010306 general physics Pseudogap |
| DOI: | 10.48550/arxiv.1903.05678 |
| Popis: | Angle-resolved photoemission spectroscopy (ARPES) measures the single-particle excitations of a many-body quantum system with energy and momentum resolution, providing detailed information about strongly interacting materials1. ARPES directly probes fermion pairing, and hence is a natural technique to study the development of superconductivity in systems ranging from high-temperature superconductors to unitary Fermi gases. In these systems, a remnant gap-like feature persists in the normal state2. Developing a quantitative understanding of these so-called pseudogap regimes may elucidate details about the pairing mechanisms that lead to superconductivity, but this is difficult in real materials partly because the microscopic Hamiltonian is not known. Here, we report on the development of ARPES to study strongly interacting fermions in an optical lattice using a quantum gas microscope. We benchmark the technique by measuring the occupied single-particle spectral function of an attractive Fermi–Hubbard system across the BCS–BEC crossover and comparing the results to those of quantum Monte Carlo calculations. We find evidence for a pseudogap that opens well above the expected critical temperature for superfluidity. This technique may also be applied to the doped repulsive Hubbard model, which is expected to exhibit a pseudogap at temperatures close to those achieved in recent experiments3. A technique analogous to angle-resolved photoemission spectroscopy used in materials characterization has been developed for interacting Fermi gases in an optical lattice, providing information on the single-particle excitations in a many-body system. |
| Databáze: | OpenAIRE |
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