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Abstracts
I5.1
Solitons and spin-charge correlations in strongly interacting Fermi
gases
Martin Zwierlein
Massachusetts Institute of Technology, Cambridge, USA
Ultracold atomic Fermi gases near Feshbach resonances or in optical lattices
realize paradigmatic, strongly interacting forms of fermionic matter. Topological
excitations and spin-charge correlations can be directly imaged in real time. In
resonant fermionic superfluids, we observe the cascade of solitonic excitations
following a pi phase imprint. A planar soliton decays, via the snake instability,
into vortex rings and long-lived solitonic vortices. For fermions in optical lattices,
realizing the Fermi-Hubbard model, we detect charge and antiferromagnetic
spin correlations with single-site resolution. At low fillings, the Pauli and
correlation hole is directly revealed. In the Mott insulating state, we observe strong
doublon-hole correlations, which should play an important role for transport.
O5.1
Emergence of Metallic Quantum Solid Phases in a Rydberg-Dressed
Fermi Gas
Chung-Yu Mou
Department of Physics, National Tsing Hua University, Hsinchu, Taiwan, ROC
We examine possible low-temperature phases of a repulsively Rydberg-dressed
Fermi gas in a three-dimensional free space. It is shown that the collective density
excitations develop a roton minimum, which is softened at a wavevector smaller
than the Fermi wavevector when the particle density is above a critical value.
The mean field calculation shows that unlike the insulating charge density waves
states often observed in conventional condensed matters, a self-assembled metallic
density wave state emerges at low temperatures. In particular, the density wave
state supports a Fermi surface and a body-center-cubic crystal order at the
same time with the estimated critical temperature being about one-tenth of the
non-interacting Fermi energy. Our results suggest the emergency of a fermionic
quantum solid that should be observable in current experimental setup.
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