Direct Observation of the Quantum Energy Gap in S = 1/2 Tetragonal Cuprate Antiferromagnets

Abstract

Using an electron spin resonance spectrometer covering a wide range of frequency and magnetic field, we have measured the low energy excitations of the S=1/2 tetragonal antiferromagnets, Sr_{2}CuO_{2}Cl_{2} and Sr_{2}Cu_{3}O_{4}Cl_{2}. Our observation of in-plane energy gaps of order 0.1 meV at zero external magnetic field are consistent with a spin wave calculation, which includes several kinds of quantum fluctuations that remove frustration. Results agree with other experiments and with exchange anisotropy parameters determined from a five band Hubbard model.

4 pages, 3 figures

Cited by in corpus (10)

• Phase Diagram and Entanglement of Ising Model With Dzyaloshinskii-Moriya Interaction
• Induced effects of the Dzyaloshinskii-Moriya interaction on the thermal entanglement in spin-1/2 Heisenberg chains
• Anomalous mirror symmetry breaking in a model insulating cuprate Sr${}_2$CuO${}_2$Cl${}_2$
• Neutron Scattering study of Sr_2Cu_3O_4Cl_2
• Field dependence of the magnetic spectrum in anisotropic and Dzyaloshinskii-Moriya antiferromagnets: I. Theory
• Field dependence of the magnetic spectrum in anisotropic and Dzyaloshinskii-Moriya antiferromagnets: II. Raman spectroscopy
• Exploring d-Wave Magnetism in Cuprates from Oxygen Moments
• High-speed antiferromagnetic domain walls driven by coherent spin waves
• Theoretical investigation of the behavior of CuSe2O5 compound in high magnetic fields
• Quantum corrections to the spin-wave spectrum of La${}_2$CuO${}_4$ in an external magnetic field