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Far infrared study of the two dimensional dimer spin system SrCu_2(BO_3)_2

T. Room·U. Nagel·E. Lippmaa·H. Kageyama·K. Onizuka·Y. Ueda
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Abstract

Using far-infrared spectroscopy in magnetic fields up to 12T we have studied a two-dimensional dimer spin gap system SrCu_2(BO_3)_2. We found several infrared active modes in the dimerized state (below 10K) in the frequency range from 3 to 100cm^-1. The measured splitting from the ground state to the excited triplet M_S=0 sublevel is Delta_1=24.2cm^-1 and the other two triplet state sublevels in zero magnetic field are 1.4cm^-1 below and above the M_S=0 sublevel. Another multiplet is at Delta_2=37.6cm^-1 from the ground state. A strong electric dipole active transition polarized in the (ab)-plane is activated in the dimer spin system below 15K at 52cm^-1.

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T. Room, U. Nagel, E. Lippmaa, H. Kageyama, K. Onizuka, Y. Ueda. 2000-03-10. Far infrared study of the two dimensional dimer spin system SrCu_2(BO_3)_2. https://doi.org/10.1103/physrevb.61.14342

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