1,047 research outputs found
Coupled Ferromagnetic and Nematic Ordering of Fermions in an Optical Flux Lattice
Ultracold atoms in Raman-dressed optical lattices allow for effective
momentum-dependent interactions among single-species fermions originating from
short-range s-wave interactions. These dressed-state interactions combined with
very flat bands encountered in the recently introduced optical flux lattices
push the Stoner instability towards weaker repulsive interactions, making it
accessible with current experiments. As a consequence of the coupling between
spin and orbital degrees of freedom, the magnetic phase features Ising nematic
order.Comment: 5 pages, 4 figures (published version
Composite fermion dynamics in half-filled Landau levels of graphene
We report on exact-diagonalization studies of correlated many-electron states
in the half-filled Landau levels of graphene, including pseudospin (valley)
degeneracy. We demonstrate that the polarized Fermi sea of non-interacting
composite fermions remains stable against a pairing transition in the lowest
two Landau levels. However, it undergoes spontaneous depolarization, which is
unprotected owing to the lack of single-particle pseudospin splitting. These
results suggest the absence of the Pfaffian phase in graphene.Comment: 3 pages, 4 figures (revision: reference update
The spiritual value of ecosystem services: an initial Christian exploration
An analysis of conceptualisations of spiritual value in the ecosystem services literature and of nature in Christian, biblical thought. Plus suggestions on how Christian approaches to decision-making could contribute to this field
Neutral Fermion Excitations in the Moore-Read state at \nu=5/2
We present evidence supporting the weakly paired Moore-Read phase in the
half-filled second Landau level, focusing on some of the qualitative features
of its excitations. Based on numerical studies, we show that systems with odd
particle number at the flux can be interpreted as a neutral
fermion mode of one unpaired fermion, which is gapped. The mode is found to
have two distinct minima, providing a signature that could be observed by
photoluminescence. In the presence of two quasiparticles the same neutral
fermion excitation is shown to be gapless, confirming expectations for
non-Abelian statistics of the Ising model with degenerate fusion channels 1 and
.Comment: 4 pages, 4 figures; v2: final published versio
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