Laser spectroscopic probing of coexisting superfluid and insulating states of an atomic Bose-Hubbard system

• Kato, Shinya

• Inaba, Kensuke

• Sugawa, Seiji

• Shibata, Kosuke

• Yamamoto, Ryuta

• Takahashi, Yoshiro

• Yamashita, Makoto

Abstract

A system of ultracold atoms in an optical lattice has been regarded as an ideal quantum simulator for a Hubbard model with extremely high controllability of the system parameters. While making use of the controllability, a comprehensive measurement across the weakly to strongly interacting regimes in the Hubbard model to discuss the quantum many-body state is still limited. Here we observe a great change in the excitation energy spectra across the two regimes in an atomic Bose–Hubbard system by using a spectroscopic technique, which can resolve the site occupancy in the lattice. By quantitatively comparing the observed spectra and numerical simulations based on sum rule relations and a binary fluid treatment under a finite temperature Gutzwiller approximation, we show that the spectra reflect the coexistence of a delocalized superfluid state and a localized insulating state across the two regimes.

Journal

• Nature Communications

  Nature Communications 7 11341-, 2016-04-20

  Nature Publishing Group

Keywords

• General Physics and Astronomy
• General Biochemistry, Genetics and Molecular Biology
• General Chemistry
• Multidisciplinary

Details

• CRID: 1050564285791616896
• NII Article ID: 120005829446
• ISSN: 20411723
• DOI: 10.1038/ncomms11341
• HANDLE: 2433/216424
• Web Site: https://www.nature.com/articles/ncomms11341.pdf
• Web Site: https://www.nature.com/articles/ncomms11341
• Text Lang: en
• Article Type: journal article
• Data Source:
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  • Crossref
  • CiNii Articles
  • KAKEN