Hidden dimer order in the quantum compass model

作者：Brzezicki Wojciech^*; Oles Andrzej M

来源：Physical Review B, 2010, 82(6): 060401.

DOI：10.1103/PhysRevB.82.060401

We introduce an exact spin transformation that maps frustrated Z(i,j)Z(i,j+1) and X(i,j)X(i+1),(j) spin interactions along the rows and columns of the quantum compass model (QCM) on an L X L square lattice to (L-1) X (L-1) quantum spin models with 2 (L-1) classical spins. Using the symmetry properties we unravel the hidden dimer order in the QCM, with equal two-dimer correlations < X(i,i)X(i+1,i)X(k,l)X(k+1,l)> and < X(i,i)X(i+1,i)X(l,k)X(l+1,k)> in the ground state, which is independent of the actual interactions. This order coexists with Ising-type spin correlations which decay with distance.

• 出版日期2010-8-12