TY - JOUR
T1 - Optical studies of gap, exchange, and hopping energies in the insulating cuprates
AU - Cooper, S. L.
AU - Thomas, G. A.
AU - Millis, A. J.
AU - Sulewski, P. E.
AU - Orenstein, J.
AU - Rapkine, D. H.
AU - Cheong, S. W.
AU - Trevor, P. L.
PY - 1990
Y1 - 1990
N2 - We have measured the insulating energy gap and the exchange interaction J in a series of cuprate crystals, including T-phase M2CuO4 (M=Pr, Nd, Sm, Eu, and Gd), T*-phase La,Tb,Sr2CuO4, and T-phase La2CuO4. We find that the energy gap scales predominantly with the in-plane Cu-O distance, scaling as loglogd-6. Furthermore, contrary to simple expectations, the energy gap increases with decreasing Cu-O distance, suggesting that Coulomb and other repulsive energies dominate the effects of band hybridization. Using a three-band Hubbard-model expression, our studies of and J in the cuprates allow us to estimate that the hopping energy t scales with Cu-O distance as logt/ logd-4.
AB - We have measured the insulating energy gap and the exchange interaction J in a series of cuprate crystals, including T-phase M2CuO4 (M=Pr, Nd, Sm, Eu, and Gd), T*-phase La,Tb,Sr2CuO4, and T-phase La2CuO4. We find that the energy gap scales predominantly with the in-plane Cu-O distance, scaling as loglogd-6. Furthermore, contrary to simple expectations, the energy gap increases with decreasing Cu-O distance, suggesting that Coulomb and other repulsive energies dominate the effects of band hybridization. Using a three-band Hubbard-model expression, our studies of and J in the cuprates allow us to estimate that the hopping energy t scales with Cu-O distance as logt/ logd-4.
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U2 - 10.1103/PhysRevB.42.10785
DO - 10.1103/PhysRevB.42.10785
M3 - Article
AN - SCOPUS:0000390943
VL - 42
SP - 10785
EP - 10788
JO - Physical Review B
JF - Physical Review B
SN - 0163-1829
IS - 16
ER -