Deconfined quantum criticality driven by Dirac fermions in SU(2) antiferromagnets

Journal Article · Thu May 15 04:00:00 EDT 2008 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.77.195101· OSTI ID:21143543

Nogueira, Flavio S ^[1]

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1. Institut fuer Theoretische Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for the so-called algebraic quantum liquids. A new type of such a liquid, the algebraic charge liquid, has been proposed recently in the context of deconfined quantum critical points [R. K. Kaul et al., Nat. Phys. 4, 28 (2008)]. In this context, by using the renormalization group in d=4-{epsilon} space-time dimensions, we show that a deconfined quantum critical point occurs in a SU(2) system provided the number of Dirac fermion species N{sub f}{>=}4. The calculations are done in a representation where the Dirac fermions are given by four-component spinors. The critical exponents are calculated for several values of N{sub f}. In particular, for N{sub f}=4 and {epsilon}=1 (d=2+1), the anomalous dimension of the Neel field is given by {eta}{sub N}=1/3, with a correlation length exponent {nu}=1/2. These values considerably change for N{sub f}>4. For instance, for N{sub f}=6, we find {eta}{sub N}{approx_equal}0.75 191 and {nu}{approx_equal}0.660 09. We also investigate the effect of chiral symmetry breaking and analyze the scaling behavior of the chiral holon susceptibility, G{sub {chi}}(x){identical_to}<{psi}(x){psi}(x){psi}(0){psi}(0)>.

• OSTI ID: 21143543
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 19 Vol. 77; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANOMALOUS DIMENSION
ANTIFERROMAGNETISM
CHIRAL SYMMETRY
CHIRALITY
CORRELATIONS
CRITICALITY
FERMIONS
GAUGE INVARIANCE
LIQUIDS
MANY-DIMENSIONAL CALCULATIONS
QUANTUM ELECTRODYNAMICS
RENORMALIZATION
SCALING
SPACE-TIME
SPINORS
SU-2 GROUPS
SYMMETRY BREAKING