Unified description of pairing, trionic and quarteting states for one-dimensional SU(4) attractive fermions

¹  Department of Theoretical Physics, Research School of Physics and Engineering, Australian National University Canberra ACT 0200, Australia
²  Mathematical Sciences Institute, Australian National University - Canberra ACT 0200, Australia
³  Nonlinear Physics Centre and ARC Centre of Excellence for Quantum-Atom Optics, Research School of Physics and Engineering, Australian National University - Canberra ACT 0200, Australia

Corresponding author: Murray.Batchelor@anu.edu.au

Received: 15 April 2009
Accepted: 19 May 2009

Abstract

Paired states, trions and quarteting states in one-dimensional attractive fermions are investigated via exact Bethe ansatz calculations. In particular, quantum phase transitions are identified and calculated from the quarteting phase into normal Fermi liquid, trionic states and spin-2 paired states which belong to the universality class of linear field-dependent magnetization in the vicinity of critical points. Moreover, unified exact results for the ground-state energy, chemical potentials and complete phase diagrams for isospin S = 1/2,  1,  3/2 attractive fermions with external fields are presented. Also identified are the magnetization plateaux of and , where M_s is the magnetization saturation value. The universality of finite-size corrections and collective dispersion relations provides a further test ground for low-energy effective field theory.