Issue
EPL
Volume 86, Number 5, June 2009
Article Number 50003
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/86/50003
Published online 17 June 2009
EPL, 86 (2009) 50003
DOI: 10.1209/0295-5075/86/50003

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

X. W. Guan1, M. T. Batchelor1, 2, C. Lee3 and J. Y. Lee1

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

Murray.Batchelor@anu.edu.au

received 15 April 2009; accepted in final form 19 May 2009; published June 2009
published online 17 June 2009

Abstract
Paired states, trions and quarteting states in one-dimensional SU(4) 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 mz = Ms/3 and mz = 2Ms/3, where Ms 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.

PACS
03.75.Ss - Degenerate Fermi gases.
03.75.Hh - Static properties of condensates; thermodynamical, statistical, and structural properties.
02.30.Ik - Integrable systems.

© EPLA 2009