Volume 78, Number 1, April 2007
Article Number 17005
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 15 March 2007
EPL, 78 (2007) 17005
DOI: 10.1209/0295-5075/78/17005

Role of symmetry in the interplay of $\mth{T=0}$ quantum-phase transitions with unconventional $\mth{T>0}$ transport properties in integrable quantum lattice systems

J. M. P. Carmelo1, 2, S.-J. Gu3 and N. M. R. Peres1

1  GCEP-Center of Physics, U. Minho, Campus Gualtar - P-4710-057 Braga, Portugal
2  Massachusetts Institute of Technology - Cambridge, MA 02139-4307, USA
3  Department of Physics and ITP, The Chinese University of Hong Kong - Hong Kong, China

received 2 October 2006; accepted in final form 13 February 2007; published April 2007
published online 15 March 2007

We show that a generalized charge SU(2) symmetry of the one-dimensional (1D) Hubbard model in an infinitesimal flux $\phi $ generates half-filling states from metallic states which lead to a finite charge stiffness D(T) at finite temperature T, whose T-dependence we study. Our results are of general nature for many integrable quantum lattice systems, reveal the microscopic mechanisms behind their exotic T > 0 transport properties and the interplay with T=0 quantum-phase transitions, and contribute to the further understanding of the transport of charge in systems of interacting ultracold fermionic atoms in 1D optical lattices, quasi-1D compounds, and 1D nanostructures.

72.10.-d - Theory of electronic transport; scattering mechanisms.
71.27.+a - Strongly correlated electron systems; heavy fermions.
05.60.Gg - Quantum transport.

© Europhysics Letters Association 2007