Spectral functions of strongly interacting isospin-1/2 bosons in one dimension

Phys Rev Lett. 2008 Oct 24;101(17):170403. doi: 10.1103/PhysRevLett.101.170403. Epub 2008 Oct 23.


We study a system of one-dimensional (iso)spin-1/2 bosons in the regime of strong repulsive interactions. We argue that the low-energy spectrum of the system consists of acoustic density waves and the spin excitations described by an effective ferromagnetic spin chain with a small exchange constant J. We use this description to compute the dynamic spin structure factor and the spectral functions of the system.