Andrew J A James

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Spin-1 condensates in the polar (antiferromagnetic) phase in two dimensions are shown to undergo a transition of the Ising type, in addition to the expected Kosterlitz-Thouless (KT) transition of half-vortices, due to the quadratic Zeeman effect. We establish the phase diagram in terms of temperature and the strength of the Zeeman effect using Monte Carlo(More)
We investigate the high-energy magnetic excitation spectrum of the high-T(c) cuprate superconductor Bi(2)Sr(2)CaCu(2)O(8+δ) (Bi-2212) using Cu L(3) edge resonant inelastic x-ray scattering. Broad, dispersive magnetic excitations are observed, with a zone boundary energy of ∼ 300 meV and a weak dependence on doping. These excitations are strikingly similar(More)
We consider a gas of two species of fermions with population imbalance. Using the renormalization group in d=1+ϵ spatial dimensions, we show that for spinless fermions and 2>ϵ>0 a fixed point appears at finite attractive coupling where the quasiparticle residue vanishes, and identify this with the transition to Larkin-Ovchinnikov-Fulde-Ferrell order(More)
We review two important non-perturbative approaches for extracting the physics of low- dimensional strongly correlated quantum systems. Firstly, we start by providing a comprehensive review of non-Abelian bosonization. This includes an introduction to the basic elements of confor- mal field theory as applied to systems with a current algebra, and we orient(More)
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