Pseudofermion dynamical theory for the spin dynamical correlation functions of the half-filled 1D Hubbard model

A modified version of the metallic-phase pseudofermion dynamical theory (PDT) of the 1D Hubbard model is introduced for the spin dynamical correlation functions of the half-filled 1D Hubbard model Mott– Hubbard phase. The Mott–Hubbard insulator phase PDT is applied to the study of the model longitudinal and transverse spin dynamical structure factors at finite magnetic field h, focusing in particular on the sin- gularities at excitation energies in the vicinity of the lower thresholds. The relation of our theoretical results to both condensed-matter and ultra-cold atom systems is discussed.

We thank D.K. Campbell, A. Moreno, and P.D. Sacramento for illuminating discussions and the support by the Beijing CSRC and the FEDER through the COMPETE Program and the Portuguese FCT in the framework of the Strategic Projects PEST-C/FIS/UI0607/2013, PEst-OE/FIS/UI0091/2014, and UID/CTM/04540/2013.