Elementary excitations of antiferromagnetic spin-1 bosons in an optical lattice

Abstract

We study elementary excitations of spin-1 bosons with antiferromagnetic interaction in an optical lattice by applying the Gutzwiller approximation to the spin-1 Bose-Hubbard model. There appear various excitations associated with spin degrees of freedom in the Mott-insulator (MI) phase as well as in the superfluid (SF) phase. In this system, the ground state in the MI phase is known to exhibit a remarkable effect of even-odd parity of particle filling, in which even fillings stabilize the MI state due to formation of spin-singlet pairs. We find that excitation spectra in the MI phase exhibit characteristic features that reflect the even-odd parity effect of the ground state. We clarify evolution of elementary excitations across the quantum critical point of the SF-MI transition.

7 pages, 2 figures, proceedings of QFS2013

References in corpus (5)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• The `Higgs' Amplitude Mode at the Two-Dimensional Superfluid-Mott Insulator Transition
• Detecting the Amplitude Mode of Strongly Interacting Lattice Bosons by Bragg Scattering
• The Amplitude Mode in the Quantum Phase Model
• First-order phase transition and anomalous hysteresis of Bose gases in optical lattices

Cited by in corpus (3)

• First-order superfluid to Mott-insulator phase transitions in spinor condensates
• Static and Dynamic Properties of Interacting Spin-1 Bosons in an Optical Lattice
• Stability of supercurrents in a superfluid phase of spin-1 bosons in an optical lattice