1205.4329 (S. Di Matteo et al.)

Orbital currents, anapoles, and magnetic quadrupoles in CuO    [PDF]

S. Di Matteo, M. R. Norman

We show that orbital currents in a CuO2 plane, if present, should be described by two independent parity and time-reversal odd order parameters, a toroidal dipole (anapole) and a magnetic quadrupole. Based on this, we derive the resonant X-ray diffraction cross-section for monoclinic CuO at the antiferromagnetic wavevector and show that the two order parameters can be disentangled. From our analysis, we examine a recent claim of detecting anapoles in CuO.

View original: http://arxiv.org/abs/1205.4329