14,168 research outputs found
Ground-state fidelity of Luttinger liquids: A wave functional approach
We use a wave functional approach to calculate the fidelity of ground states
in the Luttinger liquid universality class of one-dimensional gapless quantum
many-body systems. The ground-state wave functionals are discussed using both
the Schrodinger (functional differential equation) formulation and a path
integral formulation. The fidelity between Luttinger liquids with Luttinger
parameters K and K' is found to decay exponentially with system size, and to
obey the symmetry F(K,K')=F(1/K,1/K') as a consequence of a duality in the
bosonization description of Luttinger liquids.Comment: 13 pages, IOP single-column format. Sec. 3 expanded with discussion
of short-distance cut-off. Some typos corrected. Ref. 44 in v2 is now
footnote 2 (moved by copy editor). Published versio
Phase diagram of a Bose-Fermi mixture in a one-dimensional optical lattice in terms of fidelity and entanglement
We study the ground-state phase diagram of a Bose-Fermi mixture loaded in a
one-dimensional optical lattice by computing the ground-state fidelity and
quantum entanglement. We find that the fidelity is able to signal quantum phase
transitions between the Luttinger liquid phase, the density-wave phase, and the
phase separation state of the system; and the concurrence can be used to signal
the transition between the density-wave phase and the Ising phase.Comment: 4 pages 3 figure
Multistage Random Growing Small-World Networks with Power-law degree Distribution
In this paper, a simply rule that generates scale-free networks with very
large clustering coefficient and very small average distance is presented.
These networks are called {\bf Multistage Random Growing Networks}(MRGN) as the
adding process of a new node to the network is composed of two stages. The
analytic results of power-law exponent and clustering coefficient
are obtained, which agree with the simulation results approximately.
In addition, the average distance of the networks increases logarithmical with
the number of the network vertices is proved analytically. Since many real-life
networks are both scale-free and small-world networks, MRGN may perform well in
mimicking reality.Comment: 3 figures, 4 page
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