Magnetic-Field-Induced insulator-conductor transition in SU(2) quenched lattice gauge theory

P. V. Buividovich (1) , Maxim N. Chernodub (2) , D. E. Kharzeev (3) , T. Kalaydzhyan , E. V. Luschevskaya (1) , M. I. Polikarpov (1)

1 ITEP - Institute of Theoretical and Experimental Physics [Moscow]
2 LMPT - Laboratoire de Mathématiques et Physique Théorique
3 BNL - Physics Department

We study the correlator of two vector currents in quenched SU(2) lattice gauge theory with chirally invariant lattice Dirac operator with constant external magnetic field. It is found that in the confinement phase the correlator of the components of the current parallel to the magnetic field decays much slower than in the absence of magnetic field, while for other components the correlation length slightly decreases. We apply the Maximal Entropy Method to extract the spectral function which corresponds to this correlator. The value of this spectral function in the limit of zero frequency yields, by virtue of the Green-Kubo relations, the electric conductivity of quenched lattice gauge theory. We find that in the confinement phase the external magnetic field induces nonzero electric conductivity along the direction of the field, transforming the system from an insulator into an anisotropic conductor. In the deconfinement phase the conductivity does not exhibit any sizable dependence on the magnetic field.

Mots clés: Strong magnetic field; quantum chromodynamics; confinement; insulator-metal transition

Domaines: Physique des Hautes Energies - Réseau [hep-lat]; Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique des Hautes Energies - Théorie [hep-th]

P. V. Buividovich, Maxim N. Chernodub, D. E. Kharzeev, T. Kalaydzhyan, E. V. Luschevskaya, et al.. Magnetic-Field-Induced insulator-conductor transition in SU(2) quenched lattice gauge theory. Physical Review Letters, 2010, 105 (13), pp.132001. ⟨10.1103/PhysRevLett.105.132001⟩. ⟨hal-00463057⟩