A. M. Tsvelik

Logarithmic operators and hidden continuous symmetry in critical disordered models

Abstract We study the model of (2 + 1)-dimensional relativistic fermions in a random non-Abelian gauge potential at criticality. The exact solution shows that the operator expansion contains a conserved current — a generator of a continuous symmetry. The presence of this operator changes the operator product expansion and gives rise to logarithmic contributions to the correlation functions at the critical point. We calculate the distribution function of the local density of states in this model and find that it follows the famous log-normal law.

Experimental Realization of a 2D Fractional Quantum Spin Liquid

The ground-state ordering and dynamics of the two-dimensional S = 1/2 frustrated Heisenberg antiferromagnet Cs(2)CuCl(4) are explored using neutron scattering in high magnetic fields. We find that the dynamic correlations show a highly dispersive continuum of excited states, characteristic of the resonating valence bond state, arising from pairs of S = 1/2 spinons. Quantum renormalization factors for the excitation energies (1.65) and incommensuration (0.56) are large.

COUPLED LADDERS IN A MAGNETIC FIELD

We investigate the phase transitions in two-legs ladder systems in the incommensurate phase, for which the gap is destroyed by a magnetic field

Antiferromagnetic spin ladders: Crossover between spin S=1/2 and S=1 chains

{(h}_{c1}lh)

A CHERN-SIMONS EFFECTIVE FIELD THEORY FOR THE PFAFFIAN QUANTUM HALL STATE

and the ladder is not yet totally saturated

Two-dimensional superconducting fluctuations in stripe-ordered La1.875Ba0.125CuO4.

(hl{h}_{c2})

Disorder effects in two-dimensional d-wave superconductors.

. We compute quantitatively the correlation functions as a function of the magnetic field for an isolated strong-coupling ladder

Liouville Theory as a Model for Prelocalized States in Disordered Conductors.

{J}_{\ensuremath{\perp}}\ensuremath{\gg}{J}_{\ensuremath{\Vert}}

One-Dimensional Spin-Liquid without Magnon Excitations

and use it to study the phase transition occurring in a three-dimensional array of antiferromagnetically coupled ladders. The three-dimensional ordering is in the universality class of Bose condensation of hard-core bosons. We compute the critical temperature

Long-range magnetic ordering in Na2IrO3

{T}_{c}(h)