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arXiv · 1010.6141

Field-Induced Gap in a Quantum Spin-1/2 Chain in a Strong Magnetic Field

S. A. Zvyagin·E. Čižmár·M. Ozerov·J. Wosnitza·R. Feyerherm·S. R. Manmana·F. Mila
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Abstract

Magnetic excitations in copper pyrimidine dinitrate, a spin-1/2 antiferromagnetic chain with alternating $g$-tensor and Dzyaloshinskii-Moriya interactions that exhibits a field-induced spin gap, are probed by means of pulsed-field electron spin resonance spectroscopy. In particular, we report on a minimum of the gap in the vicinity of the saturation field $H_{sat}=48.5$ T associated with a transition from the sine-Gordon region (with soliton-breather elementary excitations) to a spin-polarized state (with magnon excitations). This interpretation is fully confirmed by the quantitative agreement over the entire field range of the experimental data with the DMRG investigation of the spin-1/2 Heisenberg chain with a staggered transverse field.

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S. A. Zvyagin, E. Čižmár, M. Ozerov, J. Wosnitza, R. Feyerherm, S. R. Manmana, F. Mila. 2010-10-29. Field-Induced Gap in a Quantum Spin-1/2 Chain in a Strong Magnetic Field. https://doi.org/10.1103/physrevb.83.060409

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