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Scalar chiral ground states of spin ladders with four-spin exchanges

Tsutomu Momoi·Toshiya Hikihara·Masaaki Nakamura·Xiao Hu
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Abstract

We show that scalar chiral order can be induced by four-spin exchanges in the two-leg spin ladder, using the spin-chirality duality transformation and matrix-product ansatz. Scalar-chiral-ordered states are found to be exact ground states in a family of spin ladder models. In this scalar chiral phase, there is a finite energy gap above the doubly degenerate ground states and a $Z_2 \times Z_2 \times Z_2$ symmetry is fully broken. It is also shown that the SU(4)-symmetric model, which is self-dual under the duality transformation, is on a multicritical point surrounded by the staggered dimer phase, the staggered scalar chiral phase, and the gapless phase.

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Tsutomu Momoi, Toshiya Hikihara, Masaaki Nakamura, Xiao Hu. 2003-04-04. Scalar chiral ground states of spin ladders with four-spin exchanges. https://doi.org/10.1103/physrevb.67.174410

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