Effect of orbital currents on the restricted optical sum rule

Benfatto, L.; Sharapov, S. G.; Beck, H.

Effect of orbital currents on the restricted optical sum rule

Authors

Benfatto, L.

Sharapov, S. G.

Beck, H.

Description

We derive the restricted optical-conductivity sum rule for a model with circulating orbital currents. It is shown that an unusual coupling of the vector potential to the interaction term of the model Hamiltonian results in a non-standard form of the sum rule. As a consequence, the temperature dependence of the restricted spectral weight could be compatible with existing experimental data for high-$T_c$ cuprates above the critical temperature $T_c$. We extend our results to the superconducting state, and comment on the differences and analogies between these two symmetry-breaking phenomena.
Revised version, to appear in EPJB