Send to

Choose Destination
Phys Rev Lett. 2006 Mar 17;96(10):106401. Epub 2006 Mar 14.

Helical liquid and the edge of quantum spin Hall systems.

Author information

Department of Physics, Stanford University, California 94305, USA.


The edge states of the recently proposed quantum spin Hall systems constitute a new symmetry class of one-dimensional liquids dubbed the "helical liquid," where the spin orientation is determined by the direction of electron motion. We prove a no-go theorem which states that a helical liquid with an odd number of components cannot be constructed in a purely 1D lattice system. In a helical liquid with an odd number of components, a uniform gap in the ground state can appear when the time-reversal symmetry is spontaneously broken by interactions. On the other hand, a correlated two-particle backscattering term by an impurity can become relevant while keeping the time-reversal invariance.

Supplemental Content

Full text links

Icon for American Physical Society
Loading ...
Support Center