2,098 research outputs found
Magnetic Catalysis: A Review
We give an overview of the magnetic catalysis phenomenon. In the framework of
quantum field theory, magnetic catalysis is broadly defined as an enhancement
of dynamical symmetry breaking by an external magnetic field. We start from a
brief discussion of spontaneous symmetry breaking and the role of a magnetic
field in its a dynamics. This is followed by a detailed presentation of the
essential features of the phenomenon. In particular, we emphasize that the
dimensional reduction plays a profound role in the pairing dynamics in a
magnetic field. Using the general nature of underlying physics and its
robustness with respect to interaction types and model content, we argue that
magnetic catalysis is a universal and model-independent phenomenon. In support
of this claim, we show how magnetic catalysis is realized in various models
with short-range and long-range interactions. We argue that the general nature
of the phenomenon implies a wide range of potential applications: from certain
types of solid state systems to models in cosmology, particle and nuclear
physics. We finish the review with general remarks about magnetic catalysis and
an outlook for future research.Comment: 37 pages, to appear in Lect. Notes Phys. "Strongly interacting matter
in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A.
Schmitt, H.-U. Yee. Version 2: references adde
Aspects of the pseudo Chiral Magnetic Effect in 2D Weyl-Dirac Matter
A connection is established between the continuum limit of the low-energy
tight-binding description of graphene immersed in an in-plane magnetic field
and the Chiral Magnetic Effect in Quantum Chromodynamics. A combination of mass
gaps that explicitly breaks the equivalence of the Dirac cones, favoring an
imbalance of pseudo-chiralities, is the essential ingredient to generate a
non-dissipative electric current along the external field. Currents, number
densities and condensates generated from this setup are investigated for
different hierarchies of the energy scales involved.Comment: 12 pages, 8 figures. Several text improvements. Accepted for
publication in European Physical Journal
Quantum Electrodynamics in Two-Dimensions at Finite Temperature. Thermofield Bosonization Approach
The Schwinger model at finite temperature is analyzed using the Thermofield
Dynamics formalism. The operator solution due to Lowenstein and Swieca is
generalized to the case of finite temperature within the thermofield
bosonization approach. The general properties of the statistical-mechanical
ensemble averages of observables in the Hilbert subspace of gauge invariant
thermal states are discussed. The bare charge and chirality of the Fermi
thermofields are screened, giving rise to an infinite number of mutually
orthogonal thermal ground states. One consequence of the bare charge and
chirality selection rule at finite temperature is that there are innumerably
many thermal vacuum states with the same total charge and chirality of the
doubled system. The fermion charge and chirality selection rules at finite
temperature turn out to imply the existence of a family of thermal theta vacua
states parametrized with the same number of parameters as in zero temperature
case. We compute the thermal theta-vacuum expectation value of the mass
operator and show that the analytic expression of the chiral condensate for any
temperature is easily obtained within this approach, as well as, the
corresponding high-temperature behavior
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