Direct measurement of the Zak phase in topological Bloch bands

View/ Open
Author
Atala, Marcos
Aidelsburger, Monika
Barreiro, Julio T.
Bloch, Immanuel
Published Version
https://doi.org/10.1038/nphys2790Metadata
Show full item recordCitation
Atala, Marcos, Monika Aidelsburger, Julio T. Barreiro, Dmitry Abanin, Takuya Kitagawa, Eugene Demler, and Immanuel Bloch. 2013. “Direct Measurement of the Zak Phase in Topological Bloch Bands.” Nat Phys 9 (12) (November 3): 795–800.Abstract
Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the band theory of solids. Here we report on the measurement of the geometric phase acquired by cold atoms moving in one-dimensional optical lattices. Using a combination of Bloch oscillations and Ramsey interferometry, we extract the Zak phase—the Berry phase gained during the adiabatic motion of a particle across the Brillouin zone—which can be viewed as an invariant characterizing the topological properties of the band. For a dimerized lattice, which models polyacetylene, we measure a difference of the Zak phase δφZak = 0.97(2)π for the two possible polyacetylene phases with different dimerization. The two dimerized phases therefore belong to different topological classes, such that for a filled band, domain walls have fractional quantum numbers. Our work establishes a new general approach for probing the topological structure of Bloch bands inoptical lattices.Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:12150777
Collections
- FAS Scholarly Articles [18176]
Contact administrator regarding this item (to report mistakes or request changes)