1207.6834 (Jay D. Sau et al.)

Collective modes of the $d$-density wave state and its relevance to
high-$T_c$ cuprates    [PDF]

Jay D. Sau, Ipsita Mandal, Sumanta Tewari, Sudip Chakravarty

We calculate the collective mode spectra of the $d$-density wave state, proposed to describe the anomalous phenomenology of the cuprates in the pseudogap regime. Even though the state breaks translational symmetry by a lattice spacing and is described by a particle-hole singlet order parameter condensing at the wave vector $q=Q=(\pi,\pi)$, interestingly, we find that the amplitude collective mode spectrum can have inelastic peaks at both $q=(0,0)$ and $q=Q=(\pi,\pi)$. In general, the spectra is non-universal, and, depending on the microscopic parameters, can have one or two peaks in the two-dimensional Brillouin zone, signifying confluence of two kinds of magnetic excitations. Our theory should be important in interpreting inelastic neutron scattering experiments in high-$T_c$ cuprates, where such multiple magnetic excitations are implicated.

View original: http://arxiv.org/abs/1207.6834