Chitra, R and Pati, Swapan and Krishnamurthy, HR and Sen, Diptiman and Ramasesha, S
(1995)
*Density-matrix renormalization-group studies of the spin-1/2 Heisenberg system with dimerization and frustration.*
In: Physical Review B: Condensed Matter, 52
(9).
pp. 6581-6587.

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## Abstract

Using the density-matrix renormalization-group technique, we study the ground-state phase diagram and other low-energy properties of an isotropic antiferromagnetic spin-1/2 chain with both dimerization and frustration, i.e., an alternation delta of the nearest-neighbor exchanges and a next-nearest-neighbor exchange J(2). For delta = 0, the system is gapless for J(2) < J(2c) and has a gap for J(2) > J(2c) where J(2c) is about 0.241. For J(2) = J(2c) the gap above the ground state grows as delta to the power 0.667 +/- 0.001. In the J(2)-delta plane, there is a disorder line 2J(2) + delta = 1. To the left of this line, the peak in the static structure factor S(q) is at q(max) = pi (Neel phase), while to the right of the line, q(max) decreases from pi to pi/2 as J(2) is increased to large values (spiral phase). For delta = 1, the system is equivalent to two coupled chains as on a ladder and it is gapped for all values of the interchain coupling.

Item Type: | Journal Article |
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Additional Information: | Copyright of this article belongs to The American Physical Society. |

Department/Centre: | Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Physical & Mathematical Sciences > Centre for Theoretical Studies |

Date Deposited: | 15 Jun 2011 09:00 |

Last Modified: | 15 Jun 2011 09:00 |

URI: | http://eprints.iisc.ernet.in/id/eprint/37520 |

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