5,248 research outputs found
Neutral Color Superconductivity Including Inhomogeneous Phases at Finite Temperature
We investigate neutral quark matter with homogeneous and inhomogeneous color
condensates at finite temperature in the frame of an extended NJL model. By
calculating the Meissner masses squared and gap susceptibility, the uniform
color superconductor is stable only in a temperature window close to the
critical temperature and becomes unstable against LOFF phase, mixed phase and
gluonic phase at low temperatures. The introduction of the inhomogeneous phases
leads to disappearance of the strange intermediate temperature 2SC/g2SC and
changes the phase diagram of neutral dense quark matter significantly.Comment: 12 pages, 7 figures. v2: references added, accepted for publication
in PRD. V3: Calculation of the neutral LOFF state clarified, typos corrected
Effect of Breaking on Chiral Phase Structure and Pion Superfluidity at Finite Isospin Chemical Potential
We investigate the isospin chemical potential effect in the frame of SU(2)
Nambu-Jona-Lasinio model. When the isospin chemical potential is less than the
vacuum pion mass, the phase structure with two chiral phase transition lines
does not happen due to breaking of QCD. When the isospin chemical
potential is larger than the vacuum pion mass, the ground state of the system
is a Bose-Einstein condensate of charged pions.Comment: Talk presented at Conference on Non-Perturbative Quantum Field
Theory: Lattice and Beyond, Guangzhou, China, Dec.16--18, 2004; v2: error
correcte
Classification of Symmetry-Protected Phases for Interacting Fermions in Two Dimensions
Recently, it has been shown that two-dimensional bosonic symmetry-protected
topological(SPT) phases with on-site unitary symmetry can be completely
classified by the group cohomology class . Later, group
super-cohomology class was proposed as a partial classification for SPT phases
of interacting fermions. In this work, we revisit this problem based on the
mathematical framework of -extension of unitary braided tensor
category(UBTC) theory. We first reproduce the partial classifications given by
group super-cohomology, then we show that with an additional structure, a complete classification of SPT phases for
two-dimensional interacting fermion systems for a total symmetry group
can be achieved. We also discuss the classification of
interacting fermionic SPT phases protected by time-reversal symmetry.Comment: references added; published versio
MMP for locally stable families and wall crossing for moduli of stable pairs
We construct reduction and wall-crossing morphisms between the moduli spaces
of stable pairs as the coefficients vary, generalizing the earlier work of
Ascher, Bejleri, Inchiostro and Patakfalvi which deals with the klt case. Along
the proof, we show that one can run the MMP with scaling on normal locally
stable families over a normal base, and that the existence of good minimal
models is preserved when reducing coefficients away from zero.Comment: 35 pages, comments welcom
Magnetic Stability Analysis for Abelian and Non-Abelian Superconductors
We investigate the origin of Abelian and non-Abelian type magnetic
instabilities induced by Fermi surface mismatch between the two pairing
fermions in a non-relativistic model. The Abelian type instability occurs only
in gapless state and the Meissner mass squared becomes divergent at the
gapless-gapped transition point, while the non-Abelian type instability happens
in both gapless and gapped states and the divergence vanishes. The non-Abelian
type instability can be cured in strong coupling region.Comment: 7 pages, 2 figures, more references added, accepted for publication
in PR
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