Broken time-reversal symmetry in strongly correlated ladder structures

Phys Rev Lett. 2003 May 9;90(18):186401. doi: 10.1103/PhysRevLett.90.186401. Epub 2003 May 5.

Abstract

We provide, for the first time, in a doped strongly correlated system (two-leg ladder), a controlled theoretical demonstration of the existence of a state in which long-range ordered orbital currents are arranged in a staggered pattern, coexisting with a charge density wave. The method used is the highly accurate density-matrix renormalization group technique. This brings us closer to recent proposals that this order is realized in the enigmatic pseudogap phase of the cuprate high temperature superconductors.