TY - JOUR
T1 - Dynamics of Hubbard-band quasiparticles in disordered optical lattices
AU - Scarola, V. W.
AU - Demarco, B.
N1 - Publisher Copyright:
©2015 American Physical Society.
PY - 2015/11/30
Y1 - 2015/11/30
N2 - Quantum degenerate gases trapped in optical lattices are ideal test beds for fundamental physics because these systems are tunable, well characterized, and isolated from the environment. Controlled disorder can be introduced to explore suppression of quantum diffusion in the absence of conventional dephasing mechanisms such as phonons, which are unavoidable in experiments on electronic solids. Recent experiments use transport of degenerate Fermi gases in optical lattices [S. S. Kondov, Phys. Rev. Lett. 114, 083002 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.083002] to probe extreme regimes. These experiments find evidence for an intriguing insulating phase where quantum diffusion is completely suppressed by strong disorder. Quantitative interpretation of these experiments remains an open problem that requires inclusion of nonzero entropy, strong interaction, and trapping in an Anderson-Hubbard model. We argue that the suppression of transport can be thought of as localization of Hubbard-band quasiparticles. We construct a theory of dynamics of Hubbard-band quasiparticles tailored to trapped optical lattice experiments. We compare the theory directly with center-of-mass transport experiments of Kondov et al. with no fitting parameters. The close agreement between theory and experiments shows that the suppression of transport is only partly due to finite-entropy effects. We argue that the complete suppression of transport is consistent with short-time, finite-size precursors of Anderson localization of Hubbard-band quasiparticles. The combination of our theoretical framework and optical lattice experiments offers an important platform for studying localization in isolated many-body quantum systems.
AB - Quantum degenerate gases trapped in optical lattices are ideal test beds for fundamental physics because these systems are tunable, well characterized, and isolated from the environment. Controlled disorder can be introduced to explore suppression of quantum diffusion in the absence of conventional dephasing mechanisms such as phonons, which are unavoidable in experiments on electronic solids. Recent experiments use transport of degenerate Fermi gases in optical lattices [S. S. Kondov, Phys. Rev. Lett. 114, 083002 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.083002] to probe extreme regimes. These experiments find evidence for an intriguing insulating phase where quantum diffusion is completely suppressed by strong disorder. Quantitative interpretation of these experiments remains an open problem that requires inclusion of nonzero entropy, strong interaction, and trapping in an Anderson-Hubbard model. We argue that the suppression of transport can be thought of as localization of Hubbard-band quasiparticles. We construct a theory of dynamics of Hubbard-band quasiparticles tailored to trapped optical lattice experiments. We compare the theory directly with center-of-mass transport experiments of Kondov et al. with no fitting parameters. The close agreement between theory and experiments shows that the suppression of transport is only partly due to finite-entropy effects. We argue that the complete suppression of transport is consistent with short-time, finite-size precursors of Anderson localization of Hubbard-band quasiparticles. The combination of our theoretical framework and optical lattice experiments offers an important platform for studying localization in isolated many-body quantum systems.
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U2 - 10.1103/PhysRevA.92.053628
DO - 10.1103/PhysRevA.92.053628
M3 - Article
AN - SCOPUS:84950129200
SN - 1050-2947
VL - 92
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 5
M1 - 053628
ER -