arXiv subjects

Amir Moghaddam

Publications and source records attributed to Amir Moghaddam.

3 recordsLinked to original sources

arXiv2015

Exact solution of the p+ip Hamiltonian revisited: duality relations in the hole-pair picture

We study the exact Bethe Ansatz solution of the p+ip Hamiltonian in a form whereby quantum numbers of states refer to hole-pairs, rather than particle-pairs used in previous studies. We find an asymmetry between these approaches. For the attractive system states in the strong pairing regime take the form of a quasi-condensate involving two distinct hole-pair creation operators. An analogous feature is not observed in the particle-pair picture.

math-ph↗

arXiv2013

BCS model with asymmetric pair scattering: a non-Hermitian, exactly solvable Hamiltonian exhibiting generalised exclusion statistics

We demonstrate the occurrence of free quasi-particle excitations obeying generalised exclusion statistics in a BCS model with asymmetric pair scattering. The results are derived from an exact solution of the Hamiltonian, which was obtained via the algebraic Bethe ansatz utilising the representation theory of an underlying Yangian algebra. The free quasi-particle excitations are associated to highest-weight states of the Yangian algebra, corresponding to a class of analytic solutions of the Bethe ansatz equations.

nlin.SI↗

arXiv2012

Deconfined quantum criticality and generalised exclusion statistics in a non-hermitian BCS model

We present a pairing Hamiltonian of the Bardeen-Cooper-Schrieffer form which exhibits two quantum critical lines of deconfined excitations. This conclusion is drawn using the exact Bethe ansatz equations of the model which admit a class of simple, analytic solutions. The deconfined excitations obey generalised exclusion statistics. A notable property of the Hamiltonian is that it is non-hermitian. Although it does not have a real spectrum for all choices of coupling parameters, we provide a rigorous argument to establish that real spectra occur on the critical lines. The critical lines are found to be invariant under a renormalisation group map.

cond-mat.supr-con↗